James Conner suffered an AC joint injury on Monday night and left Heinz Field with his right arm in a sling.
Conner rushed 23 times for 145 yards and a touchdown in the Pittsburgh Steelers 27-14 win over the Miami Dolphins.
He was injured near the two-minute warning in the fourth quarter.
The Steelers could have issues at running back against the Indianapolis Colts on Sunday. In addition to Conner\'s injury, Benny Snell is being evaluated for a knee injury. Jaylen Samuels is coming back from arthroscopic knee surgery performed less than a month ago.