It doesn’t sound like a strength issue.
When playing is your upper body in an organized position? And are you able to maintain a stabilized organized position through movement?
I recommend watching this webinar The Athletic Shoulder: Anatomy, Physiology & Function to increase your knowledge and understanding of the shoulder.
Doesn’t sound like this is a surgery situation.
Have you experienced trauma to your shoulder?
Do you have restrictions within your rom, internal/external rotation?