I'm dealing with the same thing. My best advice is to do exercises that involve the rotation of the shoulder joint.
http://www.physioroom.com/experts/askth ... 050225.php
These exercises are designed to do at home but I recommend doing them at the gym with a cable machine and LOW weight. Also, don't do these exercises at the beginning of a workout, do them at the very end. In fact, I recommend you to not do many workouts like bench or military press, as you could injure your shoulder even further.
Good luck, hope you make a full recovery.