Rotator cuff involves several soft tissue structures around the shoulder joint and each one is critical in its normal function. Since weight lifting is much more taxing on this gravity dependent joint, it's highly suggested that you take a break from the training schedules and undergo physiotherapy sessions to heal and strengthen your shoulder. Consult with a physiotherapist with the investigation reports for an exercise protocol of the injured structure. It may need as much as twelve weeks to regain normal function of your shoulder.