Minnesota Vikings All Pro running back Dalvin Cook left Sunday's game against the San Francisco 49ers with an apparent serious upper body injury.

The Vikings were trailing 31-26 as Cook took a hard hit to the chest area. He fumbled on the play, recovered by the 49ers.

Cook was carted off the field, as teammates came over to support him.

Dalvin Cook was being held in check by the 49ers defense, with only 39 yards rushing. However, Cook had six catches for 64 yards before leaving the field.

The Minnesota Vikings are in a battle with the 49ers for a wild card berth. Both teams entered the game Sunday at 5-5. Minnesota has been in just about every game this season, seemingly winning or losing at the end of each game.

Alexander Mattison took over rushing duties for the Vikings in Cook's absence. Mattison has proven in his brief NFL career that he is a capable backup.

Cook struggled with injuries his first couple seasons in the NFL. But, Cook rushed for over 1,100 yards two seasons ago and over 1,500 yards last season. He also scored 29 rushing touchdowns over those two seasons, including 16 last year. He has become one of the most feared and respected running backs in the league in the process.

The injury is a big blow to the Vikings, as they look to overcome a 1-3 start to the season.