Humeral avulsion of the glenohumeral ligament (HAGL) is defined as a disruption of the fibers of the inferior glenohumeral ligament at its humeral insertion. It is a relatively rare but important entity, given its diagnostic and clinical implications and growing debate around the treatment of adolescent patients particularly those who participate in sports. While well described in the orthopedic literature, HAGL has not been often discussed in the radiology literature. This case report presents classic imaging characteristics of HAGL in an adolescent football player. In addition, this case report addresses the epidemiology, the causes, the subtypes, and some aspects of treatment of HAGL.