The Buffalo Bills' already banged-up linebacking group could be down another key player after Paul Posluszny sustained what's being described as a potential long-term knee injury on Sunday.

Coach Chan Gailey said it's too early to determine the severity of the injury to Posluszny because the player is scheduled to have further tests following a 15-10 season-opening loss to Miami. Though Gailey said the injury could be "short term," he didn't rule out the possibility that it could be significant.

Posluszny was hurt on the first play of the third quarter when he was one of three Bills defenders to bring down running back Ronnie Brown along the sideline. Posluszny sat on the field for several minutes before getting up on his own.

Trainers examined Posluszny's right knee before having him jog off the field. Posluszny returned a few minutes later and ran along the sideline while wearing what appeared to be a brace before he was escorted back to the locker room.

The Bills are already thin at linebacker. Reggie Torbor did not play Sunday because of a chest injury, while Kawika Mitchell was placed on injured reserve Friday due to a foot injury.

To replace Mitchell, Buffalo signed free-agent linebacker Akin Ayodele, who was inactive on Sunday.

Buffalo reserve free safety Cary Harris did not return after pulling a hamstring. Gailey said it was too early to determine the severity of the injury.

Dolphins rookie first-round draft pick DE Jared Odrick did not return after leaving the field in the third quarter with a foot injury.