OBJECTIVES: This study was designed to examine the possibility of self-protective changes in athletic identity (AI) being initiated after the occurrence of a severe injury. METHOD: People (72 men and 36 women) undergoing anterior cruciate ligament (ACL) surgery and rehabilitation were asked to complete a measure of AI prior to surgery and measures of AI and rehabilitation progress at approximately 6, 12, and 24 months after surgery. RESULTS: A repeated-measures ANCOVA controlling for age and gender indicated that AI decreased significantly across the 24-month period following surgery, with the most substantial decline occurring between 6 and 12 months postsurgery. Significantly greater decreases in AI were observed among participants whose rehabilitation progress was slowest from 6 to 12 months postsurgery. CONCLUSIONS: The findings suggest that some participants reduced their identification with the athlete role in response to the threat to a positive self-image posed by their ACL injuries and the difficulties they encountered in postoperative rehabilitation.