Full-thickness rotator cuff tears in the young athlete are a rare injury. These injuries typically result from an acute traumatic event in a contact athlete, as opposed to overuse injuries more commonly seen in throwing athletes. Acute tears may be initially overlooked, with the symptoms attributed to other, more common causes, such as cuff contusion or brachial plexus neuropraxia ("stinger" or "burner"). If undiagnosed, the tear may progress to an irreparable state at the time of eventual diagnosis. Therefore, rotator cuff tear must be included in the differential for acute shoulder injuries in the young athlete. This article presents a case of an adolescent athlete with a traumatic, massive rotator cuff tear that was diagnosed and managed promptly with excellent outcome.