Minnesota Vikings head coach Mike Zimmer on Monday morning confirmed that star rookie running back Dalvin Cook did indeed tear his ACL in Sunday’s loss to the Detroit Lions.

Cook suffered the injury on a non-contact play, which is never a good sign. The scene on the sideline in Minnesota also suggested this was a serious injury, an inevitability the Vikings themselves feared following the game.

Tasked with replacing futue Hall of Famer Adrian Peterson in the Vikings’ backfield, Cook finishes his rookie season with 444 total yards and two touchdowns in four games.

With Cook now out of action, expect the combination of Jerick McKinnon and Latavius Murray to share time in Minnesota’s backfield for the remainder of the season.