Cornerback Bryant McFadden will miss at least five games with a broken forearm, injured in the fourth quarter Sunday against the Bengals.

McFadden had surgery on his arm yesterday morning.

McFadden arrived at the Steelers' training site yesterday with his right arm in a sling and what appeared to be a soft cast. He was injured on the same play in which safety Troy Polamalu left with a head injury.

Doctors likely will want to evaluate Polamalu as the week goes on. Coach Mike Tomlin said Sunday night that Polamalu was "dinged" after his helmet flew off his head when he hit Cincinnati Bengals running back Cedric Benson.

Polamalu has had at least six concussions playing high school, college and pro football, most recently Nov. 12, 2006 against New Orleans.

Deshea Townsend likely will return to start at left cornerback, where he began the season, and William Gay would move up as the nickel back because of McFadden's injury.

When Polamalu left the game in Cincinnati, veteran Tyrone Carter replaced him.

James Harrison is tied with former Steelers linebacker Joey Porter for second in the NFL with 8.5 sacks, one spot behind DeMarcus Ware (9.0) of Dallas. LaMarr Woodley is fourth with 7.5.

Harrison, Woodley and Lawrence Timmons had two sacks apiece in the seven-sack onslaught of Cincinnati quarterback Ryan Fitzpatrick.

"They are really tough up front," Fitzpatrick said. "I kept saying throughout the week that they were relentless. That's what people were telling me. That's what I could see on film and they are. At the end of the game they pinned their ears back and came after us. They are definitely a good defense. There is a reason why they are consistently in the top five or 10 in the league every year."

Not all of the Bengals thought Hines Ward's block that broke linebacker Keith Rivers' jaw was illegal.

"It's part of the game," Cincinnati linebacker Brandon Johnson said. "It was a good block. If I was in Hines Ward's shoes, I probably would have taken the same shot. You can't really blame him. But like I said, if he was playing quarterback, then there would have been a flag."

The Steelers have allowed 89 points, second fewest in the NFL only to Tennessee's 66. ... They rank No. 1 on defense, allowing 228.3 yards per game -- No. 1 against the pass at 158.7 and No. 2 against the run at 69.7. ... Kicker Jeff Reed is 10 of 10 on field-goal attempts, one of only four kickers in the league perfect on every try with at least 10 made.