Clark Haggans is out with a groin tear. Fellow starting outside linebacker Joey Porter is questionable with a knee injury. And the Steelers could potentially be shorthanded on defense Monday night when they face a San Diego Chargers team with "no real weakness," according to coach Bill Cowher.
Cowher did not elaborate on Porter's knee problem, though the right outside linebacker is seven weeks removed from cartilage-repairing arthroscopic surgery that forced him out of most of training camp and all of the preseason. He practiced Monday. The Steelers were off yesterday.
Porter had just one tackle in a 23-20 loss to the New England Patriots on Sept. 25 at Heinz Field. He has eight tackles, two sacks and a forced fumble in three games.
Cowher was asked last week if Porter was able to go full throttle.
"Oh yeah, I think he's very close," said Cowher. "Whether it's full (throttle), I don't know, but it's very, very close."
The Steelers would be forced to scramble if Porter can't play Monday, given Haggans is out (a minimum of four games) and James Harrison, the top backup at both outside linebacker positions, is already manning Haggans' left outside linebacker spot.
Rookie free agent Andre Frazier and defensive end Brett Keisel are the top candidates to replace Porter. Cowher also said rookie fifth-round draft pick Rian Wallace, who'd been working at inside linebacker in the Steelers' 3-4 scheme, is learning to play the outside.
"We're working Rian Wallace as the fourth guy," Cowher said. "Brett Keisel has been out there; he's been out there most of the year as the emergency guy. But Andre will work both sides and that's something he's been doing. From the standpoint of the bye week, we were able to do a lot of work with him on that."
The Steelers were impressed with Frazier at the University of Cincinnati and immediately signed him after the draft. The biggest obstacle for Frazier was learning to play from a standup position at the outside linebacker spot -- which requires pass-coverage skills -- after playing as a down lineman at defensive end throughout his collegiate career.
The Steelers cut Frazier, 6-foot-5, 234 pounds, prior to the start of the season, primarily because their numbers were low at running back and they were forced to keep seventh-round pick Noah Herron, a tailback now on the practice squad.
But Frazier was re-signed prior to the season opener against Tennessee, and responded by sacking Titans quarterback Steve McNair. For the season, he has two tackles and a sack, in addition to three special teams tackles in three games.
His specialty at Cincinnati was pressuring the quarterback -- he's second all-time with 22 1/2 sacks -- and batting down passes, thanks to his height, 38-inch vertical leap and expansive wingspan.
Keisel, 6-5, 285, has made most of his contributions on special teams in four-plus seasons with the Steelers, though he is a capable backup to Aaron Smith at defensive end. His athleticism (he can 360-degree dunk a basketball) allows the Steelers to drop him back into the outside linebacker spot when needed.
Wallace, 6-2, 243, has been de-activated the first three games. But he could get his first exposure to a regular-season NFL game against a Chargers offense that is one of the hottest in the league.
The Chargers have scored 127 points, second most in the league, and are coming off lopsided wins against the Giants, 45-23; and at the Patriots, 41-17. They outscored those teams by a combined 48-3 in the second half.
"They've got a lot of weapons," Cowher said, before adding, "You have to stop LaDainian Tomlinson. These guys have rushed for over 200 yards in the last two games. If you don't stop the run, the only thing (Drew Brees is) going to be doing is handing the ball off left and right. We have to stop the running game. We're respectful of the other elements of their game, but you have to take away their big play."