FINALLY, someone mentioned Postop PT! It is critical and will determine the speed of recovery and ultimate outcome. Two years ago (when I was only 75, shoot left handed) I had left rotator cuff repair and biceps tendon reattached. I used a CPM (continuous passive motion) machine for 6hrs/day x 2 weeks to get rapid return of range of motion. Then I started outpatient PT once a week for an additional 3 months and did strengthening exercises at the gym. I was able to comfortably hold my 11 lb 300 WM and shoot it at the range six months after surgery.@JasonAL if your dad is as hard headed as mine, make sure he sticks with the post op PT. Those folks (most of them) know what they're doing. If he follows the therapy plan his chances of recovery and not re-injuring are greatly improved.
Everybody is different going into surgery and in their recovery, but DO THE PT, starting 2 days after surgery with CPM, if prescribed. Shoulders are notorious for freezing up rapidly after injury and surgery.