Benson was signed as a free agent two weeks ago and has been trying to learn an offense that is substantially different from the one he had in Chicago. With Perry averaging only 2.6 yards per carry and fumbling five times, coach Marvin Lewis made his first notable change in the starting lineup.
The Bengals came in 0-6 with the second-worst running game in the NFL.
Steelers running back Willie Parker was out for the third straight game because of a sprained left knee. The Steelers had hoped to get Parker back coming off their bye week, but he aggravated the injury while working out during the week.
Pro Bowl nose tackle Casey Hampton was sidelined for the third consecutive game by a strained groin.