The purpose of this investigation was to examine whether components of psychological well-being (i.e., positive affect, negative affect, self-esteem, and vitality) mediated the relationship between self-determination theory (SDT) basic needs (competence, autonomy and related-ness) and perceived return-to-sport outcomes. Competitive athletes (n = 204) from Australia, Canada, and the United States completed an injury need satisfaction scale, psychological well-being inventories, and a measure of perceived return-to-sport outcomes. Mediation analysis (Baron & Kenny, 1986) revealed that positive affect partially mediated the relationship between competence and autonomy need satisfaction and a renewed perspective on sport, while negative affect, self-esteem, and vitality fully mediated the relationship between relatedness need satisfaction and return concerns. Interpretation of the findings suggests the importance of components of well-being in mediating relatedness need satisfaction on "return concerns" in a sport injury context. Prospective longitudinal designs using an SDT framework are discussed to further research in this area.