Minnesota Vikings running back Dalvin Cook is unlikely to play in the big showdown with the Green Bay Packers on Monday night because of a shoulder injury, sources told ESPN's Adam Schefter on Thursday.

Cook, the Vikings' leading rusher with 1,135 yards, was injured at the beginning of the third quarter during Sunday's 39-10 win over the Los Angeles Chargers. Cook was leading Minnesota in rushing with nine carries for 27 yards.

The Vikings can clinch a playoff berth with a victory Monday. Minnesota (10-4) trails Green Bay (11-3) by a game in the NFC North, but the Packers hold the tiebreaker.

On second-and-3 on the Vikings' first drive of the third quarter Sunday, with Minnesota leading by nine points, quarterback Kirk Cousins pitched the ball to Cook, who shuffled to his right before being wrapped up around the ankles by Chargers linebacker Denzel Perryman. Cook instantly went down and was tended to on the field by trainers. He walked to the sideline, disappeared inside the medical tent and was ruled out shortly thereafter.

The Vikings' backfield is down to Ameer Abdullah, Mike Boone and fullback C.J. Ham. Minnesota entered Week 15 without Cook's backup, rookie Alexander Mattison, who is dealing with an ankle injury.

Information from ESPN's Courtney Cronin was used in this report.