Cook suffered the injury in the third quarter of Sunday’s 14-7 loss to the Detroit Lions. Zimmer said Cook will undergo surgery and is expected to return next season.
Cook was injured on a play when he took a handoff from Case Keenum up the middle of the field for a 10-yard gain. Upon cutting to his right to avoid being tackled by Lions safety Tavon Wilson, Cook reached down to grab his left knee and fumbled the ball.
The 5-foot-10, 210-pound Cook was Minnesota’s second-round draft selection this year and rushed for 354 yards and two touchdowns in the Vikings’ first four games this season.
Latavius Murray replaced Cook as Minnesota’s primary running back Sunday and finished with 21 yards on seven carries and two receptions for eight yards.