"It's a situation where he's going to probably need surgery," Bills coach Chan Gailey said. "They could've done something and maybe got him back for the last game, but it probably wouldn't have happened that way."
The Bills have now made three roster moves this week to accommodate their injury woes. Defensive end Chris Kelsay was also put on injured reserve and linebacker Kirk Morrison was released. Hairston's move comes at a difficult time. 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 fifth round of the 2010 draft.
Wide receiver Stevie Johnson worked through most of practice, but not at full speed, according to Gailey. At cornerback, Leodis McKelvin is almost back to full speed while Aaron Williams is improving, but is still not 100 percent.
The Bills (5-7) will take on St. Louis (5-6-1) on Sunday.