Jackson gained 58 yards on 10 carries, including a 42-yard touchdown run, before leaving the game with the injury.
Rams coach Steve Spagnuolo met with the media on Monday afternoon. He addressed and updated the team's injury situation, including Jackson's status.
"It's not torn," Spagnuolo said. "It is going to be day-to-day. You have to be careful with these. So we'll see how he is. He'll get treated today and tomorrow and be in on Wednesday and we'll see where we're at."
He also said third-string running back Keith Toston has a shoulder sprain, but played through it for most of Sunday's game.
With Jackson and Toston both limited by those injuries, the Rams will have to look at what running backs are available on the free agent market and have to figure out what they want to do at that position.