Zimmer made the comments in his press conference on Monday, following the Vikings' 14-7 loss to the Detroit Lions Sunday at U.S. Bank Stadium.
The Vikings coach said Cook has a torn ACL.
"After watching the tape a couple times, I feel like there was a lot of missed opportunities there, offensively and defensively," Zimmer told reporters.
"Then when you turn the ball over three times and you don't get any on defense, you really don't have much of an opportunity to win. The guys played really hard. For the most part, a lot of guys did what they're supposed to do. We just didn't quite get the job done. They were 1-for-1 inside the five. I think we were only down there once. As far as the status of Dalvin Cook, he does have a torn ACL and we will move forward from there."
Dalvin Cook's injury did not look good at all pic.twitter.com/xCqYNW7PhB— Isaac (@WorldofIsaac) October 1, 2017
The coach said the team is "looking at everything right now" when asked about the possibility of bringing in another running back.
Zimmer said Cook will have to wait until the swelling goes down until he has surgery. Cook ran for 66 yards and a touchdown on 13 carries before the injury. He also had one catch for eight yards.
The Florida State product was injured in the third quarter when he was trying to elude Lions safety Tavon Wilson. Cook juked to his right on the play, appearing to get his left foot stuck in the turf. He left leg bent awkwardly and he grabbed at it while falling to the ground. Wilson put his helmet on the football, tackling Cook and forcing a fumble after a 10-yard gain.
The 22 year old had 354 yards and two touchdowns on 74 carries this season for Minnesota. He had the third-most rushing yards in the NFL this season through four weeks and second-most among rookies, behind Kansas City Chiefs star Kareem Hunt.
While you can't expect to see Cook until next season, the Vikings now have a pressing need to fill the position with talent.
Latavius Murray and Jerick McKinnon stepped in for Cook on Sunday. Murray ran for 21 yards on seven carries while McKinnon had no yards on his two attempts. Murray and McKinnon are currently the only (somewhat) healthy running backs on the Vikings' depth chart. McKinnon also left Sunday's game with an ankle injury. Murray told the St. Paul Pioneer Press that his ankle is still not 100 percent. The former Oakland Raiders running back had ankle surgery in March after signing with the Vikings in free agency.
“I expect him to come back and be the same that he was.” - Coach Zimmer on Dalvin Cook— Minnesota Vikings (@Vikings) October 2, 2017
If you are looking to add one of these running backs off of the waiver wire on Wednesday, look at Murray. He should see the bulk of the carries as he did on Sunday. He could be even more useful if McKinnon's ankle ailment turns out to be more serious.
The Vikings face the Chicago Bears in Week 5 in what could be a good matchup for Murray if he gets a hefty workload. He could move onto the RB2 radar for you, depending on your satiation at the position.
Murray is a depth piece for your roster for now and a decent plug and play option for a bye week in deeper leagues.