Blades vs Robins team news
He sustained a slight knee ligament strain and will be out of action for the next two weeks.
Other new on-loan midfielder Nathan Dyer is in the squad while Matthew Spring and Darius Henderson are both back from their training ground injuries.
Bristol will be without Christian Ribeiro, Steve Brooker and Jamie McCombe. Adriano Basso should continue in goal despite just coming back from a calf injury.