He showed up during the summer over-weight than what Miles wanted him (so goes the rumor mill) and was moved to FB (remember, Hester and Ridley BOTH started off as FB's that evolved into every down backs. Even Scott had a spell at FB). He hasn't carried the ball as much as the others because, frankly: 1.) there's only so many balls to go around and Ware, Ford and Blue defintely eat up their fair share--and rightly so. Then McGee is next in the pecking order and he's looked good. 2.) Gore and Hilliard have both caughed up balls in their brief game action thereby breaking the streak of successive carries by an LSU RB without a fumble at something ridiculous (wasn't it something like 400 carries without a fumble??). And Miles has ALWAYS been tough on those that fumble the ball away. One quick way to find yourself in Miles' doghouse? Fumble the ball and show up to start the season over-weight/out of shape. Hilliard will be fine. He's just having to play himself back into the team. But he is getting reps here and there. How he responds moving forward is up to him.
Miles was asked in his press conference if his fumble a game or two ago was the reason and he said in a beat around the bush way no. He didn't go further.