The Browns will elevate Mullens from their practice squad to serve as Case Keenum's backup for Thursday night's contest against the Broncos, Scott Petrak of the Elyria Chronicle-Telegram reports.
With Baker Mayfield (shoulder) ruled out for Thursday's contest, the Browns will elect to start Case Keenum and elevate Mullens to serve as his backup. The 26-year-old spent the preseason with Philadelphia, but he joined Cleveland's practice squad after Browns offensive assistant T.C. McCartney -- who coached Mullens in San Francisco -- vouched for him.