The Bengals signed Guy to the 53-man roster on Tuesday, Tom Pelissero of NFL Network reports.
Guy racked up 38 tackles (16 solo) across 17 regular-season appearances in New England last season. The veteran defensive tackle could get a chance to contribute Monday versus the Commanders, with Sheldon Rankins (hamstring), B.J. Hill (hamstring) and Kris Jenkins (thumb) all dealing with injuries.