Yes the severity of the injury will dictate even if he will need surgery. We must remember that Ashley Brignac had a torn labrum and choose to rehab for 8 months and is now pitching on limited bases.
In another post the protocal after surgery said a full return to activity in 6 months, but that is not the same as throwing a baseball. For the throwing athletes throwing usually begins at 6-8 months and it still takes some time to get the throwing arm to full strength. Before beginning to throw the athlete must have full range of motion, near full strength, and pain free. This usually takes 6 months but everyone heals at a different rate and yes alot depends on the severity.