Athletes lack sports motivation. The significance of contribution of time management and social support on sports motivation were examined. Using diagnostic research design, 170 respondents were selected through stratified random sampling. Multiple linear regression was applied. It was concluded that time management have significant influence on sports motivation, but not social support. This result partially affirms Self-Determination Theory. Future research may explore additional variables to explain student-athlete sports motivation, while school leaders and coaches may implement programs to improve time management and reallocate resources from social support activities.