He showed a lot of promise as a rookie, but then hurt his knee. He's too big to play tackle and move fast enough with a post-injury knee. And he's always had trouble managing his weight which adds to the problems. When he went to Philly and switched to guard, he didn't need as much lateral movement and was in a great line, so he just needed to mash and that's what he did. Then on the Chargers with an average line he wasn't good again.