<p>The current study examines the extent to which soccer players’ autonomous (i.e., volitional) and controlled (i.e., pressured) reasons for mastery-approach goal pursuit are related to challenge and threat appraisals for an upcoming game and, in turn, to players’ performance. We investigate these relations at both the between-player and within-player levels, allowing us to capture not only how different athletes typically regulate mastery-approach goals and appraise competitive situations, but also how these motivational dynamics fluctuate from game to game within the same athlete. The sample consisted of 467 games nested within 127 players (<i>M</i>_<i>age</i> = 26.31, <i>SD</i> = 5.51). Multilevel structural equation modeling revealed that autonomous reasons for pursuing mastery-approach goals related positively to challenge appraisals, whereas controlled reasons related positively to threat appraisals, both at the between- and the within-player level. Whereas challenge appraisals were unrelated to coach-rated performance at any level, threat appraisals related negatively to coach-rated performance at the between-player level. The discussion focuses on the importance of considering the dynamic nature of players’ goal pursuits when trying to understand player performance.</p>