Amidst the renewed "Denard to RB" talk, I was wondering something similar. Denard was essentially the featured back last season, and he couldn't make it through a full game without being banged up. Does he really have the size to take a RB's abuse all season if he was switched? Could he take on blocking duties?*
Granted, he was both the featured back and the QB, so he was a key component on nearly every single offensive play last year, so maybe only taking on RB duties would be easier on him, but I'm not so sure. Plus, he definitely wouldn't be a Hoke-certified power-running, downhill back.
(*Related question about switching Denard to WR, does he have the hands and/or route-running abilities to be a viable WR? I think a lot of people advocating position switches see his athleticism and kind of forgets about the skill sets each skill position requires.)