Pay fairness and human capital theories make different predictions about trainees’ occupational turnover in situations where trainees perceive unfair pay but receive huge potential returns from training. Therefore, the purpose of this study was to examine how pay fairness and human capital investment combined to explain why trainees are motivated to persist in employment when they perceive unfair pay. Cross-sectional survey data from 144 minor league baseball players showed that athletes perceived unfair pay but had low occupational turnover intentions because they perceived high learning achievement and expected to play in Major League Baseball eventually. Perceptions of unfair pay only increased occupational turnover intentions under certain conditions, such as when athletes had low expectations of playing at least one game in Major League Baseball in the next 3 years. The results support a framework that combines human capital theory and pay fairness theories to explain boundary conditions for trainee motivation.