Hambrick would have a shot if Emmitt were to go down or struggle. Otherwise, he figures to be #2 backup and short-yardage dude. (Note - Keep an eye on him for attitude. In the past, he's had a reputation for being grumpy or sulking when he's not featured. But if he's being bum-rapped or has learned to roll with the punches, he could help us a lot).
Cason is more of a role player. He could wind up returning punts (and possibly kickoffs) while being our 3rd down pass catching option out of the backfield. But he's still going to have to prove he's worth keeping more than Scobey, Anderson or Croom.