Carson suffered the foot injury during the first half in the Seahawks' 37-34 overtime loss to the Arizona Cardinals on Sunday. He didn't return to the game, finishing with five carries for 34 yards. He also had one reception for seven yards.
"There's something there that we could see," Carroll said of Carson's MRI on Monday. "It's just week-to-week, so we'll see what happens. We don't know. He was real determined to say, 'I can go with it,' but we won't know until the end of the week, for sure."
Carson joins a growing list of players with injuries in the Seahawks' banged-up backfield. Veteran tailback Carlos Hyde and rookie fourth-round draft pick DeeJay Dallas were the team's only available running backs by the end of Sunday night's game against Arizona.
Carson and Travis Homer were injured against the Cardinals, and Carroll said Monday he is unsure of Hyde's status for this week due to tightness in his hamstring. Carroll added that Homer has a knee bruise.
The Seahawks have no other running backs on their active roster or practice squad. Rashaad Penny -- the Seahawks' first-round pick in the 2018 NFL Draft -- is still on the physically unable to perform list because of a knee injury.
Seattle (5-1) is set to host the division rival San Francisco 49ers (4-3) on Sunday at CenturyLink Field.