PITTSBURGH -- Cincinnati Bengals safety Chinedum Ndukwe injured his left knee making a tackle during the second quarter in Pittsburgh and did not return to the Bengals' 23-7 loss to the Steelers on Sunday.
Ndukwe, who came into the game tied for fourth on the team in tackles, was hurt tackling Rashard Mendenhall on a 6-yard carry. Ndukwe's left leg became extended as he was making the stop, and several players fell on him.
Ndukwe had to be helped off the field.
The Bengals already were playing without cornerback Johnathan Joseph (ankle), who was inactive for the game. Nine other players previously were ruled out for the season with injuries.
Information from The Associated Press contributed to this report.