I can't speak to the padding issue, but I played soccer a few years ago, and would disconnect for games. It required me to give a small bolus at the beginning of the game to cover the upcoming basal that would be missed. I would also check my BG at halftime and correct as needed, and then again after the game. It wasn't perfect, but I think I could have fine-tuned it further if I'd been more willing to try (and played longer).
A friend of mine referees HS sports, and has mentioned to me that he sees several players each year wearing padded insulin pumps. He also sees several players wearing ankle monitors from the probation and parole department
I hope that you can get more detailed information. I don't think you need to give up on the idea of an insulin pump for your son.