Chadwick has been unlucky with injuries which kept him out of the team when it looked like he would get more regular run outs as a sub for Becks. I watched him on his debut in the Worthington cup away at Villa a few years back and he (along with Healy) stood out as having drive, commitment and some fair ability in a match where the bulk of our team needn't have bothered turning up.
His physical development which was necessary to make him more robust in the tackle has not come on as expected however and in his few appearances this season (and last), he has not looked as promising as he once did. It would therefore not surprise me if he moved on for a fee at the end of this season as his chance may not come again at United.
It is always sad to see the "promising" youngsters leave the fold however Fergie seldom releases players who go on to prove him wrong. Over the years the young players who suggested bigger things were ahead but left United such as Wilson, Greening, Healy, Notman, Higginbotham, Nevland, Cooke, Mulryne, Thornley, Tomlinson, O Kane, Appleton, Savage, Davies, Korovski, Johnson, Gillespie & Robins.
The jury could be said to be out on Wilson, Greening and Healy but all are quiet at present whilst of the others only Higginbotham and Gillespie could be considered as possible mistakes whilst Savage has proved to have heart although his temperament is still questionable whilst Korovski's reappearance at Brum is showing signs of the talent work permit problems denied us.
Sadly, I think Chadwick may join the larger list of near misses.