Soccer athletic performance varies across a soccer season due to training and fatigue. In addition, it is known that core stability is linked with anterior cruciate ligament (ACL) injury risk but their variations over a season are unknown. The aim of the study was to determine the evolution of core stability, athletic performance, and ACL injury risk among young high-level soccer players at four key moments of a season: pre-season (PRE), start of season (START), mid-season (MID), and the end of the season (END). Core stability scores increased until mid-season, while ACL injury risk scores (measured during sidestep cuttings and single-leg landing) decreased thanks to an injury prevention program between START and MID. These results are in line with the literature, which demonstrates that a high level of core stability is linked to a low injury risk. Evolution of athletic performance was not consistent throughout the season, being dependent on the specific phases of training performed by the athletes. Therefore, assessing core stability, athletic performance, and ACL injury risk multiple times across a soccer season could help coaches to adapt their training programs properly.