2 other things that might help: My son's physical therapist (who has worked with a lot of pro and college pitchers, as well as young ones) told us that my son might just need to plan on being a closer until he finished growing quickly. That turned out to be good advice. He also told us that growth goes in fits and starts--a kid might grow an inch in a month and then not at all for a couple of months after that. So he actually recommended that I measure my son monthly and if he was in a period of fast growth, limit his innings. By the time we tried this, the boy wasn't growing all that fast any more, so I don't know if it would have helped.