Honestly, he doesn't seem like the type, but you might somewhat be on to something. You notice players who are on these award circuits, eating more and training less, aren't quite ready for the bowl games. I think Peppers genuinely was hurt, but it had more to do with his poor conditioning leading up to the game.
That doesn't scare me once he hits the NFL though. The conditioning isn't broken (inseason) by 3-4 week layoffs in games as was the case between Michigan's last game and this one.
I don't blame LF7 and McCaffery for sitting either. It's a smart move on their part. Being that McCaffery did it too it's not like someone can make it a race issue, or a poor background issue (as McCaffery's parent were both pro athletes).