Dysfunction of the subscapularis muscle is introduced in this case report as a potential factor for consideration in the etiology and/or consequential sequelae of subacromial impingement syndrome. Although dysfunction of the supraspinatus and infraspinatus are implicated as being most commonly involved with subacromial impingement pathology, the subscapularis is often overlooked and therefore undertreated. Identifying the subscapularis' potential involvement in patients with subacromial impingement pathology may offer insight into shoulder impingement dysfunction and injury treatment options available to specifically address subscapularis dysfunction. In this manuscript, a case report is presented to highlight the signs and symptoms of subscapularis pathology concordant with subacromial impingement syndrome and provide a clinical rationale for treatment. The purpose of this case report is not to suggest a new approach to shoulder rehabilitation, but rather to prompt the consideration of subscapularis dysfunction when evaluating and treating patients with subacromial impingement pathology.