From what I've read, his knee's seem to be fine, and he even performed quite well from a physical stand-point at the combine. It's more about getting his head and his confidence right, and getting him back into the mentality that he had in high school.
In a sense, it reminds me a little bit of Skal (minus the injuries of course). Joerger got Skal to play with some confidence last year after a timid year at Kentucky, so let's see if coach can do it again!