ALLEN PARK -- The Detroit Lions have officially ruled out Theo Riddick for Sunday's game against the Miami Dolphins.

The move comes as little surprise, given Riddick wasn't able to practice this week despite coming off the bye. He's dealing with a knee injury.

Riddick has been Detroit's No. 3 running back this season, playing mostly as a pass-catcher and on third downs. He has 23 catches for 138 yards, plus eight carries for 30 yards.

Ameer Abdullah is expected to take Riddick's place behind Kerryon Johnson and LeGarrette Blount in the rotation. Abdullah, the one-time starter, has played just one game this season and no snaps on offense.

He did start at kick returner against the Packers, though, and likely will continue to serve that role now that Jamal Agnew has been lost to a knee injury. He could also be a candidate to return punts, along with Johnson, Golden Tate and TJ Jones.

Defensive end Ezekiel Ansah, guard T.J. Lang and tight end Michael Roberts are all listed as questionable for the Dolphins game. Lang has missed one game with a brain injury, while Roberts hasn't played since Week 2 because of a knee injury, and Ansah hasn't played since the opener because of a shoulder injury.