At some point during the second quarter while on special teams, Cincinnati Bengals running back Brian Leonard left the game with a rib injury. He didn't return.
Leonard is expected to have tests on Monday, including X-Rays, to determine the severity of the injury, according to Joe Reedy with the Cincinnati Enquirer.
If Leonard is unable to go this Sunday against the Steelers, it leaves BenJarvus Green-Ellis and Cedric Peerman as the only available running backs on the roster; Bernard Scott was placed on IR last week. It's entirely possible that we could be seeing a host of free agent running backs this Tuesday; when teams normally invite players for positions they need to update.