MINNEAPOLIS –Dalvin Cook is scheduled for an MRI Monday morning to determine the extent of a knee injury suffered during Sunday's game.
Vikings Head Coach Mike Zimmer said, "We're concerned about his ACL."
Cook was injured early in the third quarter.
On first-and-10 from his own 18, Cook took the handoff from Case Keenum and ran up the middle of the field. On a cut to evade Lions safety Tavon Wilson, Cook reached down toward his left knee. As he was tackled by Wilson, the ball was knocked loose from Cook's arm, and Detroit recovered the fumble.
Cook was helped off the field and did not return to the game.
Prior to the injury, the rookie had recorded 66 rushing yards on 13 carries. In the second quarter, Cook scored his second touchdown in Purple to give the Vikings a 7-3 lead.
In Cook's absence, the Vikings turned to Latavius Murray for the majority of carries to finish out the day. Murray recorded 21 rushing yards on seven attempts. He also added two catches for eight yards.
Murray said that it was tough to see Cook injured.
"Any time a teammate goes down, especially in this group and a friend of mine, you feel bad for them," he said.
Murray, who signed with Minnesota as a free agent this spring, said that as a competitor, he always has "the expectation" and the attitude to prepare as a starter.
"I don't think it really matters how it [happens that I'm starting]. I've got to be ready," Murray said. "Just like today, unfortunate things happen, so it's not about whether or not what rhythm I have. I need to be ready when my number is called."
Following the game, several teammates reacted empathetically to Cook going down but maintained that excuses can't be made. When asked by media if Cook leaving the game caused a shift in mentality for the offense, receiver Adam Thielen said he didn't think that was the case.
"I don't think that anything is going to change on our mindset. We trust the guys in that room," Thielen said. "You obviously feel for a guy like Dalvin, who's an extremely hard worker and a great guy, so hopefully everything's all right with him, and we'll be praying for him."
The Vikings have endured a number of difficult injuries over the past two-plus seasons, and Zimmer has preached a "next man up" approach that his players echo.
"You hate to see guys go down, especially young guys that are playing well and really coming into their own," said Kyle Rudolph. "Unfortunately, that's part of our game, and if you're around our game long enough, you're going to deal with it.
"You hate to see it," Rudolph added. "You just have to be there for him."
Stefon Diggs, who recorded five catches for 98 yards, said that Cook brings more than just a pair of wheels to the game.
"D.C.'s a hell of a runner. [But there's also] his morale, the persona he brings to this team," Diggs said. "We believe in him always. It sucks to see him go down, but we also have to have the 'next man up' mentality because there's a whole lot of football left. And I trust the guys we've got back there – they'll get the job done.
"Case was up after Sam [Bradford] went down, so you know how we kind of handle it when someone goes down," Diggs later said. "We're pulling for our guy to come back, but until then, you've gotta move forward."
Zimmer was asked about what changes the Vikings might have to make to the offense.
"Dalvin is a really explosive player," Zimmer said. "He has such great big-play ability, so we'll have to look at things differently, but if you lose a guy like him, you lose a lot of firepower."
Zimmer said that he had spoken with Cook and encouraged him.
"I just went in and talked to him and told him he's not the first great running back to have an ACL, if it is one, and came back pretty good," Zimmer said. "Dalvin will have a great career."