The purpose of this study is to investigate the correlation between sponsorship and the performance and development of early career athletes transitioning from junior level to professional sports, because this issue has not been fully explored in the Czech Republic. The reason is the almost absolute absence of financial or material support for such early-career athletes, when their transition from junior categories and the entire junior category is almost always exclusively financed and supported by their parents and families. We also emphasise the absolute absence of legislative provisions that would give supporters of such athletes at least a tax or other advantage. The research is based on research of Cardenas (2023), Hong and Fraser (2023) and Moolman and Shuttleworth (2023) and aims to assess how financial and material support provided by sponsors can enhance an athlete’s performance and long-term career trajectory. A mixed method approach was adopted, combining quantitative analysis through surveys and performance data with qualitative interviews. Data from 173 early career athletes from various disciplines were analysed using t-tests and ANOVA statistical methods to assess financial stability, access to better training, and community participation. Results indicate that sponsorship significantly contributes to better performance metrics, with sponsored athletes showing a 20% improvement in competition results compared to nonsponsored athletes. Furthermore, sponsorship financial support improved training opportunities and access to elite facilities, which was shown to increase athletes’ performance by 15%. However, some challenges related to sponsorship obligations, such as marketing commitments, were highlighted by athletes, underscoring the pressures that sponsorship can introduce. The implications of this study suggest that effective sponsorship strategies can play a vital role in an athlete’s career development, offering not only financial stability but also opportunities for personal branding and increased community engagement. Another implication is a possible consideration for legislators in the context of preparing a legislative framework enabling tax or other benefits for companies and organisations sponsoring or supporting these young athletes. More research is recommended to explore the long-term impact of sponsorship on athlete mental health and career sustainability, as well as the differences in sponsorship effects across various sports disciplines.