Stress fractures are annoying. They're relatively mild compared to other injuries, but if you rush back, it's really easy to reaggravate and find yourself back at square one. I spent the better part of a year hobbled by one because I couldn't keep still and rest. With his HS injuries, it sounded like he was going to need time to develop, which this will certainly hinder. I see no reason he shouldn't be good to go by the opener, but this makes it even less likely he will crack the rotation. I'd still burn the redshirt even if he only gets 5-10 minutes a game in half the non-conference games. Do what you can to keep him engaged and prep him to be a 20-minute guy as a sophomore.