Is your son's doctor an orthopedic surgeon trained in sports medicine? If not, I would take him to one. Pain on the outside of the elbow in youth pitchers can be many things, from not serious to very serious. A very serious injury is Osteochondritis Dissecans of the Elbow. I know twin boys who were diagnosed with it at 13 and 14. Their doctor - a top orthopedic surgeon trained in sports medicine who treats MLB players - attributed the injury to overuse from year round baseball.