The Vikings placed RB Adrian Peterson on injured reserve Monday and promoted rookie RB Caleb King from the practice squad.
Peterson tore the ACL in his left knee in Saturday's game against the Redskins. Head athletic trainer Eric Sugarman said Monday that the recovery time is about 8-9 months. Sugarman added that Peterson did not injure his PCL nor his LCL, but he also tore the MCL in his left knee.
King is a rookie out of Georgia. Toby Gerhart will start at running back in the team's season finale vs. Chicago.
The Vikings also waived TE Allen Reisner and promoted TE Mickey Shuler from the practice squad.