The purpose of this research was to examine the mediating roles of job autonomy and the quality of the leader–member relationship to explain the impact of organizational support on team performance. A total of 228 cases collected from Korean business organizations were used for data analysis. Hierarchical multiple regression, Type 1 SS-based general linear modeling, and structural equation modeling were used for analyses. All results were compared to examine the magnitude of the interactions of two mediating variables—job autonomy and leader–member relation quality—to predict the influence of organizational support on team performance. Results include (1) two mediating variables played partial mediating roles; (2) between the mediating variables, leader–member relations maximized the magnitude of job autonomy; (3) organizational support was the commanding predictor for team performance, while it was found to be a statistically nonsignificant factor, which did not directly influence team performance. Conclusions are described, followed by limitations and future research recommendations.