I don't think he has anything left to prove in A ball, which is why I said he'll start in AA Erie. Although, if they take it slow and give him a little more time at the highest A level before moving up, I don't think that would be a bad thing. He does seem to have the rep of being a mediocre hitting prospect, but from what I've seen, he's a real sleeper to improve.
AA tends to be a turning point for many Tiger prospects (just like with Granderson last year), so we'll just have to see. But as with all Tiger hitting prospects, it's best to temper your expectations until they make it big.