He should do what makes him happy. But my approach would be to let the game tell you when it's time to be a PO. When the coach stops putting you in the line up then it's time to be a PO! In the meantime he can of course direct his efforts to improve more in the pitching area. Kind of what my son will do with basketball. Simply doesn't have any more hours in the day to give basketball a max effort. So he will play in high school for fun til the coach cuts him. If he plays four years great. If he sits the bench by varsity also fine. If he gets cut at some point he will sit in the stands and support his classmates. Life is all about choices. You make yours then the coaches have to make theirs.