About 80 percent of people who separate their shoulders but do not completely dislocate the joint regain pain-free motion and strength by the end of a year. For the remaining 20 percent, there may be pain, stiffness, and weakness when lifting overhead. Results may be different for young athletes.
As your doctor has said, it’s impossible to know who will do well without surgery. It is also unknown how often shoulders without surgery have a second (usually worse) separation. For a young athlete interested in getting back into the game, surgery may be the best option. Follow your doctor’s advice on this.