Well from what I understand he had a back injury that took some of his power away and you combine that with being rushed too AAA and it really wasnt a suprised he struggled at the start of the season. Since he got to Trenton he has been playing like the prospect we thought he was. I think he has a 940 OPS (or around that) and he has more walks then K's in AA which I think suggests a hitter which is starting to mature. He is only 21 and in reality he should have started in AA not AAA.
EDIT: Duncan has a .947 OPS in AA. .377 OBP .570 SLG