While I agree that there is only so much improvement one can get from practice alone, a player has to show he is ready to play, or get more time on the field. And as much as we all love DeAngelo, he had some deficiencies in his game that needed to be worked out before he got more time.
but to BE READY IN YOUR HEAD- YOU HAVE TO PLAY
You hear all the time about players wanting to get that 1st play, or first game, or first playoff game out of the way.
this game is about confidence, playing in games builds that and what you get is =2008 D Williams.
Experience is everything!
With that said, he still did play a decent amount, he just didn't start. And, while I loved him as a runner, his problems in pass protection, particularly blitz pick up, and with his endurance were things he had to improve upon before he could be looked at as the feature back. IMO, those two factors had more to do with DeAngelo not starting over Foster than Fox being overly loyal to DeShaun.