ORCHARD PARK, N.Y. (AP) - Buffalo Bills offensive lineman Chris Hairston has been placed on injured reserve and will miss the rest of the season with a bruised right ankle.

Coach Chan Gailey will shuffle his line, and use rookie David Snow and also veteran Sam Young at times to replace Hairston, 23, a 6-foot-6, 330-pound right tackle out of Clemson.

The news made matters difficult for the line. Erik Pears, the team's top right tackle, has been out since Nov. 6, and is also lost for the season with a hip issue.

Buffalo signed Chris Scott off the Tennessee Titans' practice squad to the fill the roster vacancy. The 6-4, 360-pound tackle has also spent time on the practice squads of Green Bay and Tampa Bay after playing two seasons with the Steelers. He was selected by Pittsburgh in the 2010 fifth round.

The Bills (5-7) will take on St. Louis (5-6-1) on Sunday.