It'll be tough to replace Cook's production, as he has 1,067 rushing yards and six touchdowns this season. He also has 30 receptions for 221 yards.
Vikings offensive coordinator Klint Kubiak addressed Cook's absence this Thursday, telling reporters "I know he's going to be bummed out."
With Cook expected to miss Sunday's game, the Vikings have signed running back A.J. Rose to their practice squad. The former Kentucky star finished his college career with 1,971 rushing yards.
Despite signing Rose to the practice squad, Minnesota is expected to start Alexander Mattison at running back.
Kubiak expressed confidence in Mattison earlier today, saying "We have all the confidence in the world in him."
When healthy, Mattison has shown that he can handle a large workload. In 13 games this season, he has 432 rushing yards and two touchdowns. Additionally, he has 24 catches for 183 yards and a touchdown.
It'll be interesting to see how the Vikings' ground game looks on Sunday with Mattison handling the bulk of the carries.
Kickoff for the Rams-Vikings game is at 1 p.m. ET.