Best advice I can give is to take care of his arm, first and foremost. He still has another year to get healthy, develop, and get stronger. I would highly recommend that he gets in with a high level PT with lots of baseball experience and top flight baseball training facility. I would also look for a biomechanical analysis, similar to driveline. I have learned over the years how poor timing during the pitching delivery can wear down an arm much quicker and expose a player to injury.