According to Geoff Hobson of Bengals.com, Otis Hudson and Dontay Moch could return as soon as the team's home opener against the San Francisco 49ers on September 25. Both players suffered injuries at various times during the preseason, limiting their preseason to virtually zero snaps. Hudson's injury was less pronounced, originally on crutches that was later reported as a knee injury. Dontay Moch suffered a foot injury against the Carolina Panthers with initial reports suggesting he'd be out between 4-8 weeks.
Obviously when both players return, no changes will be made the 53-man roster. Since both players practiced during training camp, they were labeled ineligible for the Physically Unable to Perform list, forcing the team to keep them on the Active Roster.
As of right now Hudson is listed as the backup right guard behind Clint Boling with newly acquired Mike McGlynn backing up Kyle Cook at center and Nate Livings at left guard. Moch is listed as the team's backup strong-side linebacker behind Manny Lawson.