Published: Sep 09, 2010 6:10 PM EDT
Updated: Sep 10, 2010 4:30 AM EDT

ORCHARD PARK, N.Y. (AP) — Buffalo Bills middle linebacker Kawika Mitchell missed practice due to a foot injury and it's doubtful he'll play in the season opener against Miami on Sunday.

Coach Chan Gailey declined to divulge details of the injury Thursday, except to say Mitchell was hurt in practice a day earlier and is "doubtful" to play. Mitchell was having tests to determine what Gailey called a "short-term and long-term" prognosis, an indication the injury could be severe.

Mitchell, a seven-year NFL veteran, is a backup to Andra Davis.

The Bills are already expected to be without outside linebacker Reggie Torbor, who's recovering from a chest injury.

Gailey was optimistic starting safety Jairus Byrd (groin) will play.