The Bills officially placed RB Fred Jackson on injured reserve Tuesday and elevated DT Jay Ross to the active roster.
Jackson sprained his MCL in Sunday’s loss to the Rams. He finished last season on I.R., as well, with a fractured fibula.
Jackson, who missed two games with an LCL sprain and one with a concussion, had 437 rushing yards and 217 receiving yards this season to go along with four total touchdowns.
Ross has been with the Bills the past two seasons.