Cardinals running back Ryan Williams has been inactive for each game this season, and it doesn't look like his role is going to increase moving forward. A knee injury during training camp pushed Williams down the depth chart early on, and running backs coach Stump Mitchell thinks that is the reason Williams hasn't seen the field.

"Had he been able to [practice], he may have had the opportunity to be up," Mitchell told ESPN.com Saturday. "If he's up he has the opportunity to be in the ball games. He'll have that opportunity again next year."

Williams has played in just five games since being a second round pick in 2011, as a result of knee issues. He was surpassed by Andre Ellington, but still believes in his ability to be a to be a contributor down the road.

"Just like [coach Bruce Arians] said at the beginning of the season, everybody has a role on this team," Williams said. "And I think I figured my role out, and that's it, I'm just going to continue to work hard. Be the best player I can be for this team. Point blank."