Bills rookie cornerback Aaron Williams is out indefinitely after being wheeled off the field on a stretcher with a chest injury during a 34-31 victory over the New England Patriots on Sunday.
Bills coach Chan Gailey would only say following the come-from-behind win that Williams was having tests and it's unlikely the injury is season-ending.
Williams, Buffalo's second-round draft pick, was hurt while making a diving attempt to tackle New England wide receiver Wes Welker, who made a catch on a crossing route over the middle with 2:37 left in the third quarter.
The injury further depletes Buffalo's thin defensive secondary, which already is missing veteran Terrence McGee, who's expected to miss a few more weeks with a hamstring injury.
The Associated Press contributed to this report.