Barriers and Facilitators in the Junior-to-Senior Transition in Male Football—A Scoping Review

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Very good work, I attach a document with some suggestions.

Comments for author File: Comments.pdf

Author Response

Comments 1: 

I would say it is almost OK, but not quite "copy/paste-proof". In the Abstract the objective is formulated as "synthesising the literature... identifying barriers, facilitators and gaps", while in the Introduction it adds nuances ("characterising methodologies, mapping developments, demands/resources/coping strategies"), and in the Discussion it reverts to another wording ("reviewing and organising the literature"). These are minor differences, but they exist. I recommend unifying the same target sentence, word for word, in the Abstract, the end of the Introduction and the beginning of the Discussion.

R: Thank you very much for detecting this. We reformulated the text in order to address your comments.

Comments 2: 

Date of the scoping review

In this link doi.org/10.17605/OSF.IO/JBZXR appears that it was an update, please include in the text

R: Thanks for your comment. We did not identify this information in the protocol registration, but if there is inserted, for sure is a mistake. This review is not an update.

Comments 3: 

Eligibility criteria

The eligibility criteria are too general or abstract and should be made more operational.

Screening and reliability

You note two independent screeners with third-reviewer arbitration; add inter-rater agreement (e.g., κ with 95% CI) at title/abstract and full-text stages, plus the tool used (EndNote/Rayyan). This improves transparency of study selection.

R: thank you very much for detecting this. There was an error in the transcription of the search strategy used. As you can confirm in the protocol registration (where the syntax was also presented) there is a more accurate search strategy that has been employed, and this is the reason for the difference in the results presented in your search. Also, in the protocol you can see described the PEO strategy used, more adequate to the context of this scoping review. We add also information concerning the tool used to do the screening process (Endnote). Please not that we did not indicate the level of agreement between the researchers that perform the screening because this is not a recommendation according the best practices for systematic review. Nerveless, we introduce in the text several information concerning some of the aspects that you mentioned to clarify the paper. Once again, thank you very much for your careful analysis of our paper.

Reviewer 2 Report

Comments and Suggestions for Authors

It is important to congratulate the authors for their work, despite the fact that there are minor issues that require improvement.

Abstract

The methodology employed in conducting this research (PRISMA or an alternative approach) should be incorporated within the abstract.

This text constitutes an introduction.

It is suggested that lines 68-69 provide the reasons for leaving, thus completing the rationale with both statistical and qualitative data on the reasons that explain these withdrawals.

It is recommended that the factors influencing the transition be elucidated with greater precision, with particular emphasis on those factors that exert an impact on young players as they transition to the senior stage. This would serve to provide a more comprehensive and nuanced understanding of the underlying reasons for these transitions.

Materials and methods.

It is imperative to include the PROSPERO quality document for systematic reviews, as this is a prerequisite for this particular type of study and research. Furthermore, it is essential to ascertain that there are no similar studies in existence. This is regarded as a mandatory prerequisite for the authors.

2.1. It is imperative to elucidate the criteria that were employed in order to ensure that a particular study was not excluded from the research.

2.2. It is imperative to elucidate the methodology employed in the selection process, emphasising the utilisation of consensus as the guiding principle. In the event that the eligibility criteria have already been met, it is necessary to provide a detailed account of the reasons for the authors reaching this consensus.

It would be beneficial to ascertain whether any tests or methodologies were employed in order to assess the bias of the studies.

The commencement of the search is a pivotal point in this study, and it is imperative to ascertain the precise year in which it began.

Results

An elucidation of Figure 2 would be greatly appreciated. The document provides a concise description of the product; however, it would be beneficial to offer further elaboration to address the needs of a broader demographic.

Discussion.

Lines 287-295: An elucidation would be greatly appreciated on the nature of the preparatory programme and its potential areas of focus, given that the contribution made is of considerable interest but remains somewhat incomplete.

 

Author Response

1. Abstract:

• The methodology employed in conducting this research (PRISMA or an alternative approach) should be incorporated within the abstract.

R:  Thank you for your suggestion. We have already added the requested information in the abstract!

2. Introduction:

• It is suggested that lines 68-69 provide the reasons for leaving, thus completing the rationale with both statistical and qualitative data on the reasons that explain these withdrawals.

R: Thank you for the recommendation. We have reformulated the text to insert data on the reasons that explain these withdrawals.

• It is recommended that the factors influencing the transition be elucidated with greater precision, with particular emphasis on those factors that exert an impact on young players as they transition to the senior stage. This would serve to provide a more comprehensive and nuanced understanding of the underlying reasons for these transitions.

R: Thank you for the suggestion. We have added more information, to provide a more comprehensive and nuanced understanding of the underlying reasons for these transitions (lines 102-106).

3. Materials and methods:

• It is imperative to include the PROSPERO quality document for systematic reviews, as this is a prerequisite for this particular type of study and research. Furthermore, it is essential to ascertain that there are no similar studies in existence. This is regarded as a mandatory prerequisite for the authors.

R: We would like to acknowledge the comment of the reviewer. This review includes outcome others than health related. The Prospero only allow the registration of protocols for systematic reviews that include health related outcomes. Additionally, the PROSPERO do not allow the registration of protocols for scoping reviews. We register the protocol in OSF. A previous search in databases and protocol registration databases was done in order to confirm that are no similar reviews published (or ongoing) in this specific topic.

 

• It is imperative to elucidate the criteria that were employed in order to ensure that a particular study was not excluded from the research.
• It is imperative to elucidate the methodology employed in the selection process, emphasising the utilisation of consensus as the guiding principle. In the event that the eligibility criteria have already been met, it is necessary to provide a detailed account of the reasons for the authors reaching this consensus.

R:  Thanks for the suggestions. We added some more information concerning the inclusion/exclusion criteria. Additionally, we want to clarify that any event occurs in which all the eligibility criteria have been meet.

 

• It would be beneficial to ascertain whether any tests or methodologies were employed in order to assess the bias of the studies.

R: There was no evaluation of the bias of the study. In scoping reviews there is not a mandatory process. Nerveless, we analyse the methodological quality of the studies as described in the methods section.

 

• The commencement of the search is a pivotal point in this study, and it is imperative to ascertain the precise year in which it began.

R:  The search was performed in a single day, as described in point 2.2. There were no restrictions concerning the inclusion data of the papers, according to the best recommendations for scoping reviews.

 

4. Results:

• An elucidation of Figure 2 would be greatly appreciated. The document provides a concise description of the product; however, it would be beneficial to offer further elaboration to address the needs of a broader demographic.

R: Thanks for detecting this. We move the figure to the beginning of the section 3.3 and we introduce some explanatory text.

 

5. Discussion:

• Lines 287-295: An elucidation would be greatly appreciated on the nature of the preparatory programme and its potential areas of focus, given that the contribution made is of considerable interest but remains somewhat incomplete.

R: Thank you for the recommendation. We have revised the text to clarify the nature of the preparatory programs (or measures) that could help prevent these effects (Lines 315-320).

Reviewer 3 Report

Comments and Suggestions for Authors

Dear authors,

 

A beautiful idea, useful for practitioners by studying it and highlighting the specific aspects of the transition from juniors to seniors in a sports discipline.

I offer you my observations and recommendations below:

 

TITLE

The title emphasizes “barriers and facilitators”, but in Methods (p.3–4) no data extraction strategy is specified by categories of barriers and facilitators (in other words, I think that the procedure for coding these two dimensions (barrier/facilitator) is missing).

Exclusively male selection (p.3, r.114–117): The title does not specify “male football”, but the analysis restricts the research to men only. This aspect could be a reason to reformulate the title, especially since the proposed purpose refers only to “male”

 

AIM

The purpose is well formulated (organizing and synthesizing the scientific literature on the junior-to-senior transition in men’s football) although it is stated in different forms, in different locations in the manuscript.

But: L20-22: ”This scoping review synthesizes the scientific literature on the junior-to-senior transition, identifying key barriers, facilitators, and gaps” / L102-105: ”The aim of this review was to organize and synthesize the available scientific literature on the male junior-to-senior transition, identifying key research topics, characterizing methodologies, and mapping the evolution of studies addressing the transition demands, resources, barriers and coping strategies among academy football players”?!! I recommend a unitary, uniform formulation, throughout the manuscript. Thank you

 

INTRODUCTION

L39–105: It does not rigorously define the concepts of “barrier” and “facilitator”, although these appear in the title.

L39–105: The introduction insists on theoretical models (ATDE, Holistic Model), but neglects the physical and biological dimensions of the transition, which are later mentioned in the abstract and results.

p.2–3

L73–L92: Many cited sources are from 2000–2014 (e.g. Bloom [18]; Bronfenbrenner [25]), which gives theoretical solidity, but does not reflect the current state of empirical research in the last 5 years.

L39–105: The text only mentions “male footballers” in the Methods section (p.3, r.114–117), but the introduction gives the impression that it refers to transition in general.

L39-105: The paragraphs on failure rates (r.57–68) and theoretical models (r.70–92) are not connected by causal reasoning — there is no transition explaining why these models help to understand the problem.

I strongly recommend 2 recent articles, extremely relevant to bring a balance between theoretical (psychosocial) and empirical (physiological, biological) aspects:

Alexe DI, Čaušević D, Čović N, Rani B, Tohănean DI, Abazović E, Setiawan E, Alexe CI. The Relationship between Functional Movement Quality and Speed, Agility, and Jump Performance in Elite Female Youth Football Players. Sports. 2024; 12(8):214. https://doi.org/10.3390/sports12080214, --- Provides a physiological and biomechanical perspective on the transition to higher levels. Would complement paragraphs L93–L98, which discuss increasing physical demands and multifactorial stressors.

Čaušević D, Rani B, Gasibat Q, Čović N, Alexe CI, Pavel SI, Burchel LO, Alexe DI. Maturity-Related Variations in Morphology, Body Composition, and Somatotype Features among Young Male Football Players. Children. 2023; 10(4):721, https://doi.org/10.3390/children10040721, -- Aligns directly with passages L55–61 and L93–95, which discuss performance differences between juniors and seniors and the impact of biological maturity. Would complement the absence of a “physical” dimension in the introduction, providing recent evidence on how maturation influences selection and performance.

 

METHODS

Transparent methodology (page 3–4, L109–128) that follows the PRISMA-ScR guideline and is registered on OSF (r.111), which ensures transparency and reproducibility. The authors describe the database, search terms, and selection process (r.119–126).

The authors use recognized tools (Letts et al., Law et al.) for critical appraisal of studies, which increases rigor.

L113-117: Studies on women and non-English studies without scientific justification are excluded. A scoping review should be more inclusive and clearly explain why it is limited to men only.

 

L120-122: The syntax “football* OR football AND talent* OR …” is not logically incorrect (it uses double “football”). Correct would be: ("football*" OR "soccer") AND (talent* OR "talent identification" …); otherwise, the database returns irrelevant results. I recommend the authors to check this aspect! Maybe it is just a technical editing error. Thanks

L119-124: Only the search date (“24th March 2024”) is mentioned, but not the period covered (e.g. “from database inception to 2024”). This affects transparency and replicability.

The inclusion criteria are vague

L123–124: It is said that “EndNote 21.0” was used only for citation management, not for screening. It is not specified whether Rayyan, Covidence or Excel was used for double screening — hence the lack of technical details.

L130-156: PRISMA-ScR does not require assessment of the quality of studies; however, the authors use Letts et al. (21-item) and Law et al. (16-item). While this is not wrong, it does not explain why they did so and how they integrated the scores into the interpretation.

L125–127 / L157–158: It is stated that a third author “was consulted”, but it is not indicated whether inter-rater agreement (e.g. Cohen’s kappa) was calculated. Without this information, the reliability of the selection is unclear. I ask the authors to check and complete.

L160-163: It is stated that the data were extracted using a modified Cochrane form, but it is not explained how the content was classified according to barriers or facilitators — essential for a title that promises this. I recommend elaboration / correction. Thank you!

L160–163: It is only stated that an extraction form was used, but it is not specified how the results were synthesized: was it a thematic analysis? a narrative mapping? a conceptual framework? Complete lack of transparency in the method of data analysis.

Missing complete PRISMA diagram L178-179: "Figure 1. PRISMA flow chart" is mentioned, but the numbers are not clearly described in the text (the exclusion process by criteria is not detailed).

It is not mentioned whether grey sources (theses, reports) — relevant in a scoping review — were taken into account. It is only specified "original studies in English", without justifying the exclusion of other languages ​​(e.g. Portuguese or Spanish, relevant in football). I ask the authors to clarify and provide details. Thank you!

 

RESULTS

 

All studies have quality scores >75%, indicating a rigorous selection. However, I ask the authors to remedy / correct the following aspects:

- It is not explained how the themes were extracted and grouped. The results seem like a descriptive collage, not a systematic thematic analysis.

- Although the title of the article promises a mapping of barriers and facilitators, the authors use other labels (“performer constraints”, “task constraints”, etc.) without clearly marking what constitutes an obstacle and what a facilitating factor

- Not all numbers are reported: exact reasons for exclusion and the number of articles eliminated at each step are missing

- Only percentage averages are provided (e.g. 89.17%), without individual values ​​or distributions. It is not mentioned whether the scores influenced the interpretation of the results.

Absence of a comparative synthesis between types of factors. The relative importance of psychosocial vs. physical vs. organizational factors is not compared; they are just presented separately.

 

DISCUSSION

 

This section has a logical structure (it follows the three types of “constraints” described by the ecological model -Newell, 1986), the authors constantly compare their results with previous studies (L270–L489), and the final part offers advice for coaches and organizations (L.532–541), i.e. a good transfer to practice. However, I ask the authors to remedy / correct the following aspects:

• As in Results, the text discusses general themes (motivation, stress, social support), but does not make an explicit distinction between factors that act as barriers and those that act as facilitators. The key terms in the title almost disappear.
• The scoping review includes qualitative and quantitative studies, but the discussion treats all conclusions as equivalent. Variation in the level of evidence is not recognized.
• Many cited authors are from 2000–2010 (e.g. Wylleman, Stambulova, Bronfenbrenner). Post-2018 references are missing, for example on dual career transitions
• Although Results mentions differences in maturity, Discussion almost completely ignores them. There is no discussion of growth, somatotype, or physiological demands — crucial dimensions in the junior–senior transition.
• One purpose of a scoping review is to show “gaps in knowledge”, but the authors do not clearly list which types of studies are missing (e.g. longitudinal, female, non-European).
• Although there is a mini-section “Limitations”, it is limited to general statements (“limited by available studies”). Selection errors, language bias are not discussed
• The discussion summarizes results more than it interprets them. There are no sentences that advance new hypotheses, conceptual models or theoretical explanations.
• Suggestions are very general (“coaches should support athletes more holistically”), without concrete examples (e.g. mentoring programs, psychological monitoring, feedback dual career structure).

 

• Authors can add a subsection “Knowledge gaps and future directions”, with 3–4 clear research directions.
• Authors can expand the Limitations section to include: language bias, exclusive male selection, lack of formal coding.

 

CONCLUSIONS

I ask authors to pay close attention to the following aspects:

The terms “barriers” and “facilitators” do not appear at all in the Conclusions section. They only talk generically about “factors” and “multifactorial nature”. This is the biggest discrepancy between the title and the conclusions.

The main barriers and facilitators are not specified (for example: “psychological adaptability and social support emerged as key facilitators”). Without a clear synthesis, the reader does not retain the essential message.

Although some results referred to differences in maturity and physical loads, the conclusions completely omit these aspects.

The conclusions are correct, but general and repeat ideas already expressed.

 

REFERENCES

 

Of the 113 references, 31 are older than 10 years, which means approx. a quarter of the bibliography. I do not claim that this aspect is bad, but there are recent studies, especially on football.

I recommend completing it with post-2015 works on: ecological dynamics in football, dual career models, psychological resilience in athlete transitions, modern talent pathway frameworks etc

Author Response

1. Title:

• The title emphasizes “barriers and facilitators”, but in Methods (p.3–4) no data extraction strategy is specified by categories of barriers and facilitators (in other words, I think that the procedure for coding these two dimensions (barrier/facilitator) is missing).

R: Thank you very much for your comment. In fact, our aim was not to establish a criterion for data extraction according to the barriers and facilitators, because there is not a theoretical rationale that can help us to organize the data, and we consider that the data can be better organized according to a specific theoretical rationale. In this sense, we add new information at the beginning of section 3.3 explaining how we organized our results. The barriers and facilitators emerged from this analysis and are presented in the discussion and conclusion sections.

Exclusively male selection (p.3, r.114–117): The title does not specify “male football”, but the analysis restricts the research to men only. This aspect could be a reason to reformulate the title, especially since the proposed purpose refers only to “male”

R: Thank you for the suggestion. We have already added it.

2. Aim:

 

• The purpose is well formulated (organizing and synthesizing the scientific literature on the junior-to-senior transition in men’s football) although it is stated in different forms, in different locations in the manuscript.

But: L20-22: ”This scoping review synthesizes the scientific literature on the junior-to-senior transition, identifying key barriers, facilitators, and gaps” / L102-105: ”The aim of this review was to organize and synthesize the available scientific literature on the male junior-to-senior transition, identifying key research topics, characterizing methodologies, and mapping the evolution of studies addressing the transition demands, resources, barriers and coping strategies among academy football players”?!! I recommend a unitary, uniform formulation, throughout the manuscript. Thank you

R: Thank you for the suggestion. We have already revised the text to be consistent and uniform.

3. Introduction:

 

• L39–105: It does not rigorously define the concepts of “barrier” and “facilitator”, although these appear in the title.

R: Thank you very much for your comment. We introduce a new paragraph define the concepts of “barrier” and “facilitator”, although these appear in the title.

 

L39–105: The introduction insists on theoretical models (ATDE, Holistic Model) but neglects the physical and biological dimensions of the transition, which are later mentioned in the abstract and results.

R: We thank the reviewer for this observation; however, we respectfully clarify that the purpose of the Introduction was not to provide an exhaustive list of all known determinants of the junior-to-senior transition, but rather to introduce the theoretical frameworks most frequently used to explain how different determinants (e.g., physical, biological, psychosocial, and organizational) interact within a developmental pathway. Ecological dynamics, the Holistic Athletic Career Model, and the ATDE model were included because they offer integrative perspectives capable of situating physical and biological factors within a wider performer–environment system, rather than treating them as isolated variables. As the manuscript shows in subsequent sections and throughout the Results, physical and biological dimensions are not neglected; they are systematically reviewed as part of the performer constraints and are deeply embedded in the multifactorial nature of the transition. For conceptual clarity, the Introduction aimed to establish why the transition is multifaceted, while the Results and Discussion address which specific factors—including maturational status, physical demands, and relative age effect—shape it.

 

• L73–L92: Many cited sources are from 2000–2014 (e.g. Bloom [18]; Bronfenbrenner [25]), which gives theoretical solidity, but does not reflect the current state of empirical research in the last 5 years.

R: Thank you for your comment. In addition to our explanation in previous comment, the purpose of the introduction section was to highlight the theoretical frameworks and referential works, since the scoping review aims to synthetise (latter in the discussion and conclusion sections) the most recent available scientific evidence.

 

• L39–105: The text only mentions “male footballers” in the Methods section (p.3, r.114–117), but the introduction gives the impression that it refers to transition in general.

R: You are correct. We start from a broader context in the introduction section, that allow us to have a clear view of the current theoretical rational available, to be more specific in the methods, results, discussion and conclusion.

 

• L39-105: The paragraphs on failure rates (r.57–68) and theoretical models (r.70–92) are not connected by causal reasoning — there is no transition explaining why these models help to understand the problem.

R: Thank you very much for your suggestion. We included a new paragraph to better contextualize this transition.

 

I strongly recommend 2 recent articles, extremely relevant to bring a balance between theoretical (psychosocial) and empirical (physiological, biological) aspects:

• Alexe DI, Čaušević D, Čović N, Rani B, Tohănean DI, Abazović E, Setiawan E, Alexe CI. The Relationship between Functional Movement Quality and Speed, Agility, and Jump Performance in Elite Female Youth Football Players. Sports. 2024; 12(8):214. https://doi.org/10.3390/sports12080214, --- Provides a physiological and biomechanical perspective on the transition to higher levels. Would complement paragraphs L93–L98, which discuss increasing physical demands and multifactorial stressors.
• Čaušević D, Rani B, Gasibat Q, Čović N, Alexe CI, Pavel SI, Burchel LO, Alexe DI. Maturity-Related Variations in Morphology, Body Composition, and Somatotype Features among Young Male Football Players. Children. 2023; 10(4):721, https://doi.org/10.3390/children10040721, -- Aligns directly with passages L55–61 and L93–95, which discuss performance differences between juniors and seniors and the impact of biological maturity. Would complement the absence of a “physical” dimension in the introduction, providing recent evidence on how maturation influences selection and performance.

R: Thank you for your suggestion. We add a new paragraph to the final part of the introduction section, and we also add the two suggested references.

 

4. Methods:

 

• Transparent methodology (page 3–4, L109–128) that follows the PRISMA-ScR guideline and is registered on OSF (r.111), which ensures transparency and reproducibility. The authors describe the database, search terms, and selection process (r.119–126).

The authors use recognized tools (Letts et al., Law et al.) for critical appraisal of studies, which increases rigor.

L113-117: Studies on women and non-English studies without scientific justification are excluded. A scoping review should be more inclusive and clearly explain why it is limited to men only.

R: We appreciate the observation and acknowledge that the study could have been more inclusive by considering women’s football. However, our decision to focus exclusively on men’s football was based on the specific objective of understanding the dynamics and particular characteristics of that context, allowing for a more delimited and coherent analysis aligned with the available sample. Nonetheless, in the study’s limitations, we will explicitly mention the exclusion of women’s football, recognizing that this decision restricts the scope and generalizability of the results obtained.

 

• L120-122: The syntax “football* OR football AND talent* OR …” is not logically incorrect (it uses double “football”). Correct would be: ("football*" OR "soccer") AND (talent* OR "talent identification" …); otherwise, the database returns irrelevant results. I recommend the authors to check this aspect! Maybe it is just a technical editing error. Thanks

 

R: Thank you for your comments. First, thanks for detecting a typo in our search question. As you can confirm in the OSF protocol registration, the word soccer was included in the search question. You can also confirm all the syntax applied in each database. In this sense, we introduce the correct information in the section 2.2. 

• L119-124: Only the search date (“24th March 2024”) is mentioned, but not the period covered (e.g. “from database inception to 2024”). This affects transparency and replicability.

R: Thak you for your suggestion. A correction has been introduced.

• L123–124: It is said that “EndNote 21.0” was used only for citation management, not for screening. It is not specified whether Rayyan, Covidence or Excel was used for double screening — hence the lack of technical details.

R: Thanks for your comment. We introduce new information.

• L130-156: PRISMA-ScR does not require assessment of the quality of studies; however, the authors use Letts et al. (21-item) and Law et al. (16-item). While this is not wrong, it does not explain why they did so and how they integrated the scores into the interpretation.

R: Thanks for your comment. In fact, the evaluation of the methodological Quality of the studies is not mandatory in Scoping reviews, but it’s recommendable, when possible. In this sense and based on previous strategies used by some authors that published Scoping reviews on sport science, we decided to evaluate the methodological Quality of the studies, because this process can add important information concerning methodological aspects that the authors can improve in this area of research. In this specific case, there are no critical situations that deserve a specific mention.

• L125–127 / L157–158: It is stated that a third author “was consulted”, but it is not indicated whether inter-rater agreement (e.g. Cohen’s kappa) was calculated. Without this information, the reliability of the selection is unclear. I ask the authors to check and complete.

R: We did not calculate the inter-agreement. Since this is not mandatory, our option was to develop this process in a qualitative way.

• L160-163: It is stated that the data were extracted using a modified Cochrane form, but it is not explained how the content was classified according to barriers or facilitators — essential for a title that promises this. I recommend elaboration / correction. Thank you!

R: We appreciate this observation. To clarify, the extraction tool followed Cochrane guidance and was intended to collect structured methodological and substantive data (study characteristics, context, outcomes). Barriers and facilitators were not pre-coded at the extraction phase because many studies did not explicitly identify them (and also because there is not the objective of the extraction data). Instead, this classification was carried out during the data synthesis, where findings were interpreted within the ecological dynamics perspective and then categorized as performer, task, or environmental constraints that hindered (barriers) or supported (facilitators) the transition. We have now added a sentence in the Methods to clarify this process.

L160–163: It is only stated that an extraction form was used, but it is not specified how the results were synthesized: was it a thematic analysis? a narrative mapping? a conceptual framework? Complete lack of transparency in the method of data analysis.

R: Thanks for your comments. We introduce a new sentence explaining the rationale to extract the data (section 2.3) and a new paragraph to explain the strategy to analyse the results (section 3.3)

• Missing complete PRISMA diagram L178-179: "Figure 1. PRISMA flow chart" is mentioned, but the numbers are not clearly described in the text (the exclusion process by criteria is not detailed).

R: Thank you for detecting this. We reformulate this section.

• It is not mentioned whether grey sources (theses, reports) — relevant in a scoping review — were taken into account. It is only specified "original studies in English", without justifying the exclusion of other languages ​​(e.g. Portuguese or Spanish, relevant in football). I ask the authors to clarify and provide details. Thank you!

R: Thank you for your comment. We add some more information concerning the inclusion/exclusion criteria. Concerning the languages, we followed the logic of the international language for scientific publication.

 

5. Results:

 

All studies have quality scores >75%, indicating a rigorous selection. However, I ask the authors to remedy / correct the following aspects:

- It is not explained how the themes were extracted and grouped. The results seem like a descriptive collage, not a systematic thematic analysis.

R: We thank the reviewer for this comment. We respectfully clarify that the purpose of a scoping review is to map and organize existing evidence rather than to perform a systematic thematic analysis, which is typically used when synthesizing qualitative data only. In line with PRISMA-ScR recommendations, our objective was to present a descriptive synthesis of the available literature, identifying the main areas of focus. To improve clarity, we have added a new paragraph at the beginning of Section 3.3 explaining the rationale used to group studies. Specifically, the studies were categorized according to the ecological dynamic’s framework, which conceptualizes the junior-to-senior transition in relation to performer, task, and environmental constraints. This provides a theoretically coherent structure for organizing the findings, while remaining methodologically consistent with the aims and scope of a scoping review.

• Not all numbers are reported: exact reasons for exclusion and the number of articles eliminated at each step are missing

R: Thank you for your comment. We add new information.

• Only percentage averages are provided (e.g. 89.17%), without individual values ​​or distributions. It is not mentioned whether the scores influenced the interpretation of the results.

R: We thank the reviewer for this comment. In this review, none of the included studies received a critically low-quality rating. All studies scored above 75%, placing them within the excellent methodological range according to the criteria adopted. For this reason, there was no requirement to exclude or downgrade evidence, nor to apply differential weighting when interpreting the results. Because no study presented methodological weaknesses likely to bias the findings, the quality assessment served to confirm the robustness of the included evidence rather than to guide selective interpretation. To improve clarity, we have now specified in the manuscript that all studies exceeded the minimum quality threshold, and therefore quality scores did not influence the synthesis of results.

6. Discussion:

This section has a logical structure (it follows the three types of “constraints” described by the ecological model -Newell, 1986), the authors constantly compare their results with previous studies (L270–L489), and the final part offers advice for coaches and organizations (L.532–541), i.e. a good transfer to practice. However, I ask the authors to remedy / correct the following aspects:

• As in Results, the text discusses general themes (motivation, stress, social support) but does not make an explicit distinction between factors that act as barriers and those that act as facilitators. The key terms in the title almost disappear.

R: We thank the reviewer for this comment. Following your suggestion, we added point 4.4. in discussion section

• The scoping review includes qualitative and quantitative studies, but the discussion treats all conclusions as equivalent. Variation in the level of evidence is not recognized.

R: We appreciate your comment. Following your suggestion, we revised the discussion section to clearly distinguish between the different levels of evidence among the included studies. The text now explicitly acknowledges the variation between qualitative and quantitative studies and discusses the implications of this difference for the strength of the conclusions (Lines 300-321).

• Many cited authors are from 2000–2010 (e.g. Wylleman, Stambulova, Bronfenbrenner). Post-2018 references are missing, for example on dual career transitions

R: Thank you for your comment. In the dual career section, we cite 3 references from 2019 and 1 from 2020.

• Although Results mentions differences in maturity, Discussion almost completely ignores them. There is no discussion of growth, somatotype, or physiological demands — crucial dimensions in the junior–senior transition.

 

R: We appreciate your comment. Following your suggestion, we revised section 4.1.2.2. (Lines 455-464)

• One purpose of a scoping review is to show “gaps in knowledge”, but the authors do not clearly list which types of studies are missing (e.g. longitudinal, female, non-European).

R: We appreciate the comment but respectfully disagree. A scoping review aims primarily to map and summarize the available evidence, not to enumerate every type of study that has not been conducted (an evidence gap map was not the purpose of this study). Our goal was to synthesize the strongest existing research on the topic, rather than classify the absence of particular study designs.

• Although there is a mini-section “Limitations”, it is limited to general statements (“limited by available studies”). Selection errors, language bias are not discussed

R: Thank you for this helpful comment. We agree that the previous wording of the limitations section was too general. In the revised manuscript, we have expanded this section to explicitly address potential limitations of the study

• The discussion summarizes results more than it interprets them. There are no sentences that advance new hypotheses, conceptual models or theoretical explanations.
• Suggestions are very general (“coaches should support athletes more holistically”), without concrete examples (e.g. mentoring programs, psychological monitoring, feedback dual career structure).

R: We thank the reviewer for this comment, nerveless our point is that the purpose of scoping review is not advance new hypotheses or develop new conceptual models. In accordance with PRISMA-ScR guidelines, the primary purpose of a scoping review is to map, describe, and synthesize the existing evidence on a topic, not to generate new theoretical explanations. Our discussion therefore focuses on summarizing what the literature shows, identifying consistent patterns, and highlighting areas where evidence remains limited or absent. While we have interpreted the findings within established theoretical perspectives (particularly the ecological dynamics framework) the nature of a scoping review does not require the proposal of novel hypotheses.

• Authors can add a subsection “Knowledge gaps and future directions”, with 3–4 clear research directions.

R: Thanks for your comment. We add the text.

• Authors can expand the Limitations section to include: language bias, exclusive male selection, lack of formal coding.

R: Thanks for your comment. We think that is repeated from a previous comment that we answer.

 

7. Conclusions

I ask authors to pay close attention to the following aspects:

• The terms “barriers” and “facilitators” do not appear at all in the Conclusions section. They only talk generically about “factors” and “multifactorial nature”. This is the biggest discrepancy between the title and the conclusions.
• The main barriers and facilitators are not specified (for example: “psychological adaptability and social support emerged as key facilitators”). Without a clear synthesis, the reader does not retain the essential message.
• Although some results referred to differences in maturity and physical loads, the conclusions completely omit these aspects.
• The conclusions are correct, but general and repeat ideas already expressed.

R: Thanks for your comment. We had reformulated the conclusion section, now also including the “barriers and facilitators” on the text.

 

8. References

Of the 113 references, 31 are older than 10 years, which means approx. a quarter of the bibliography. I do not claim that this aspect is bad, but there are recent studies, especially on football.

I recommend completing it with post-2015 works on: ecological dynamics in football, dual career models, psychological resilience in athlete transitions, modern talent pathway frameworks etc

R: We appreciate the reviewer’s observation, but we respectfully disagree with the implication that the presence of references older than 10 years represents a limitation. The purpose of a scoping review is to synthesize all available evidence on a topic, regardless of publication date, and many foundational works in talent development, ecological dynamics, dual career research, and career transition theory pre-date 2015. Excluding these key studies would introduce historical bias and weaken the conceptual grounding of the review.

Additionally, the review protocol was preregistered, and the search strategy and cut-off date were clearly reported. In accordance with best practice for evidence synthesis, we did not update the database search after peer review, as this would require reopening the entire screening, extraction, and quality appraisal process. If performed at every revision stage, the project would not reach completion.

However, we agree that recent work continues to expand the field, and we have added several post-2015 references addressing ecological dynamics in football, dual career development, and psychosocial factors in athlete transitions to strengthen the currency and relevance of the manuscript.

Reviewer 4 Report

Comments and Suggestions for Authors

I first want to thank the authors for submitting this manuscript as I believe this is important to helping talent development but also talent identification. 

The first comment that I have is the breadth of information that is in this review is quite large. While I understand that this manuscript is titled a scoping review, there are several areas that I believe do not have the attention paid to it that it deserves. Specifically, the physical attributes portion. How both junior and senior is defined here is critical. Also the search criteria was not broad enough in my opinion to capture all the available literature to make sure that you did not miss anything. Below are several manuscripts that are missing from this review that provide important details to this junior to senior level transition. 

França, C.; Ihle, A.; Marques, A.; Sarmento, H.; Martins, F.; Henriques, R.; Gouveia, É.R. Physical Development Differences between Professional Soccer Players from Different Competitive Levels. Appl. Sci. 2022, 12, 7343. https://doi.org/10.3390/app12147343 

Jadczak, Łukasz¹; Grygorowicz, Monika²; Dzudziński, Witold; Śliwowski, Robert¹. Comparison of Static and Dynamic Balance at Different Levels of Sport Competition in Professional and Junior Elite Soccer Players. Journal of Strength and Conditioning Research 33(12):p 3384-3391, December 2019. 

Castagna, Carlo; Castellini, Elena. Vertical Jump Performance in Italian Male and Female National Team Soccer Players. Journal of Strength and Conditioning Research 27(4):p 1156-1161, April 2013.

Güllich, A. (2013). Selection, de-selection and progression in German football talent promotion. European Journal of Sport Science, 14(6), 530–537. https://doi.org/10.1080/17461391.2013.858371

Williams, A. M., & Reilly, T. (2000). Talent identification and development in soccer. Journal of Sports Sciences, 18(9), 657–667. https://doi.org/10.1080/02640410050120041

Mujika, I., Santisteban, J., Impellizzeri, F. M., & Castagna, C. (2009). Fitness determinants of success in men’s and women’s football. Journal of Sports Sciences, 27(2), 107–114. https://doi.org/10.1080/02640410802428071

Reeves, M. J., Roberts, S. J., McRobert, A. P., & Littlewood, M. A. (2018). Factors affecting the identification of talented junior-elite footballers: a case study. Soccer & Society, 19(8), 1106–1121.

Villaseca-Vicuña, Rodrigo, et al. "Comparison of physical fitness and anthropometric profiles among Chilean female national football teams from U17 to senior categories." Journal of Physical Education and Sport 21 (2021): 3218-3226.

 

My recommendation is to further develop specific areas of this review such as either the physical performance, performers constraints, or organizational/club environment and take out the rest. I also recommend adding soccer to your search terms. There appears to be to many missing articles from this review. 

Author Response

1. The first comment that I have is the breadth of information that is in this review is quite large. While I understand that this manuscript is titled a scoping review, there are several areas that I believe do not have the attention paid to it that it deserves. Specifically, the physical attributes portion. How both junior and senior is defined here is critical. Also the search criteria was not broad enough in my opinion to capture all the available literature to make sure that you did not miss anything. Below are several manuscripts that are missing from this review that provide important details to this junior to senior level transition.

 

França, C.; Ihle, A.; Marques, A.; Sarmento, H.; Martins, F.; Henriques, R.; Gouveia, É.R. Physical Development Differences between Professional Soccer Players from Different Competitive Levels. Appl. Sci. 2022, 12, 7343. https://doi.org/10.3390/app12147343

 

Jadczak, Łukasz¹; Grygorowicz, Monika²; Dzudziński, Witold; Śliwowski, Robert¹. Comparison of Static and Dynamic Balance at Different Levels of Sport Competition in Professional and Junior Elite Soccer Players. Journal of Strength and Conditioning Research 33(12):p 3384-3391, December 2019.

 

Castagna, Carlo; Castellini, Elena. Vertical Jump Performance in Italian Male and Female National Team Soccer Players. Journal of Strength and Conditioning Research 27(4):p 1156-1161, April 2013.

 

Güllich, A. (2013). Selection, de-selection and progression in German football talent promotion. European Journal of Sport Science, 14(6), 530–537. https://doi.org/10.1080/17461391.2013.858371

 

Williams, A. M., & Reilly, T. (2000). Talent identification and development in soccer. Journal of Sports Sciences, 18(9), 657–667. https://doi.org/10.1080/02640410050120041

 

Mujika, I., Santisteban, J., Impellizzeri, F. M., & Castagna, C. (2009). Fitness determinants of success in men’s and women’s football. Journal of Sports Sciences, 27(2), 107–114. https://doi.org/10.1080/02640410802428071

 

Reeves, M. J., Roberts, S. J., McRobert, A. P., & Littlewood, M. A. (2018). Factors affecting the identification of talented junior-elite footballers: a case study. Soccer & Society, 19(8), 1106–1121.

 

Villaseca-Vicuña, Rodrigo, et al. "Comparison of physical fitness and anthropometric profiles among Chilean female national football teams from U17 to senior categories." Journal of Physical Education and Sport 21 (2021): 3218-3226.

 

 

2. My recommendation is to further develop specific areas of this review such as either the physical performance, performers constraints, or organizational/club environment and take out the rest. I also recommend adding soccer to your search terms. There appears to be to many missing articles from this review. 

R: Thank you for your comments. First, thanks for detecting a typo in our search question. As you can confirm in the OSF protocol registration, the word soccer was included in the search question. You can also confirm all the syntax applied in each database. In this sense, we introduce the correct information in the section 2.2.  The aim of the scoping review is to have a broad range of the available literature. We do not want to develop any specific area, because the idea was to merge the similar topics after the initial search.

 We acknowledge that some papers cannot be detected by the electronic searches as well for manual searches. Nerveless, some of the studies that are mentioned do not fulfil the inclusion criteria that we established. For example, we just included papers from male footballers, and some papers mentioned before including data from females or do not specific data from gender (Mujika et al, 2009; Reeves et al, 2018; Villaseca-Vicuña et al 2021, Castagna et al 2013.), just present data form seniors (e.g., Cintia et al., 2002)  Others are “theoretical” papers, not empirical studies (e.g., William and Reilly, 2000). In this sense, we would like to maintain the initial search, acknowledging this risk (that occur in all reviews).

Our purpose in this scoping review was not to conduct an exhaustive analysis of any single determinant, but to synthesize how multiple factors interact within the junior-to-senior transition. Consistent with PRISMA-ScR guidelines, the aim was to map the breadth and complexity of the available evidence rather than conduct an in-depth examination of one specific domain.

Physical factors, biological maturation, and relative age effects were included and discussed within the category of performer constraints, alongside psychological and social aspects, in order to reflect the integrated nature of the transition rather than isolate single contributors. Improving depth in one sub-domain at the expense of others would reduce the ecological validity of the findings and undermine the review’s objective: to show how constraints interact rather than operate independently.

We have also clarified how junior and senior categories are defined in the Introduction, emphasizing that the transition refers to progression from under-19 (or equivalent academy categories) into open-age senior competition, which aligns with existing research and talent development frameworks.

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

Dear authors,

I have analyzed the new version of the manuscript. It is much clearer, better explained and structured.
I also noted your attitude of arguing and supporting some of your own points of view, without adapting or completing them, an aspect that I consider positive.
I did not find a response to this observation / comment of mine:

”” Although the title of the article promises a mapping of barriers and facilitators, the authors use other labels (“performer constraints”, “task constraints”, etc.) without clearly marking what constitutes an obstacle and what a facilitating factor””?........!, but I consider that you have provided sufficient arguments and adaptations to the manuscript.
I have no further comments.
I wish you success

Author Response

Comments 1: 

"Dear authors,

I have analyzed the new version of the manuscript. It is much clearer, better explained and structured.
I also noted your attitude of arguing and supporting some of your own points of view, without adapting or completing them, an aspect that I consider positive.
I did not find a response to this observation / comment of mine:

”” Although the title of the article promises a mapping of barriers and facilitators, the authors use other labels (“performer constraints”, “task constraints”, etc.) without clearly marking what constitutes an obstacle and what a facilitating factor””?........!, but I consider that you have provided sufficient arguments and adaptations to the manuscript.
I have no further comments.
I wish you success"

 

Response 1: 

First of all, we would like to thank you very much for your comments, which clearly benefited the creation of a better structure and logical sequence for reading our article. We tried to answer all your requests with the utmost honesty, as well as, as you said, maintaining our opinion on some issues, and we also thank you for your understanding in this situation. Regarding the missing comment, we have created a new section in the manuscript dedicated exclusively to this matter. It may have happened that the reviewer expected the response to be included in the discussion text. In any case, we have highlighted it in red in the manuscript we sent in response to the assistant editor. 

In any case, we've also included the relevant section in this comments section:

"4.4. Barriers and facilitators  Taken together, the evidence indicates that the transition from junior to senior football is shaped by a complex interplay of psychological, physical, social, and organizational factors, which can act either as barriers or facilitators of development. According to the reviewed studies, facilitators of successful progression include strong psychological skills such as resilience, self-regulation, intrinsic motivation, and goal commitment. Players capable of managing uncertainty and maintaining focus under pressure are more likely to adapt effectively to the demands of professional football. Likewise, holistic development environments characterized by consistent technical, tactical, and psychosocial support, enhance adaptability and confidence. Close coordination between academy and senior structures, involving shared methodologies, gradual exposure to first-team contexts, and coaching continuity, further supports smoother transitions. Supportive interpersonal relationships with coaches, teammates, and family, alongside dual career pathways that balance sport and education, also contribute to players’ long-term engagement and well-being. In contrast, the literature identifies several barriers that compromise the transition process. Chief among these are organiza-tional misalignments, including poor communication between development levels, inconsistent coaching philosophies, and limited opportunities for young players to experience competitive senior football. Such gaps disrupt developmental continuity and foster insecurity. Psychological barriers, including performance anxiety, lack of confidence, and limited coping strategies, often emerge when players face increased external pressure without adequate support. Moreover, early maturation advantages can distort selec-tion processes, reducing developmental opportunities for late-maturing players who might possess equal or greater potential in the long term. Overall, these findings reinforce that the success of the junior-to-senior transition depends on the alignment of individual, rela-tional, and structural dimensions. Clubs that promote coherent organizational cultures, sustain psychological support, and progres-sive exposure to senior demands are better positioned to transform emerging talent into sustained professional performance."   Thank you again for your contribution. Best regards.   João Tomás

Author Response File: Author Response.docx