Chatman injured his left knee during the Jets' 28-24 victory over Kansas City on Sunday and left the locker room on crutches. Coach Eric Mangini said on Monday that the injury appeared to be season-ending.

Chatman, who signed with the Jets as a free agent in March, missed the first four games after being suspended without pay for violating the league's steroids and related substances policy. Chatman said he tested for a diuretic — "something I never even heard of" — that could be used as a masking agent.

He had 8 yards on five carries, two receptions for 5 yards and five special teams tackles in three games.

Ainge, who has an injured right foot, was New York's fifth-round pick out of Tennessee and was inactive for every game this season. The Jets still have three quarterbacks on their roster with Brett Favre, Kellen Clemens and Brett Ratliff.