KICKOFF: Sunday, 1:00 ET
TV: FOX, Kenny Albert, Daryl Johnston, Tony Siragusa
SERIES: 19th meeting. 49ers lead series, 10-8, with victories in four of the past five meetings since 1990. The teams last played in Pittsburgh in 1996, a game the 49ers won 27-6.
PREDICTION: Steelers 23-16
KEYS TO THE GAME: 49ers offensive coordinator Jim Hostler can't hope to move the ball against a defense as fast and aggressive as the Steelers' without opening up the playbook more. RB Frank Gore is averaging just 3.8 yards per carry in large part because opponents are overplaying the run until QB Alex Smith proves he can hurt them downfield. ... The Steelers have been balanced offensively thus far, but the 49ers are the first opponent with enough quality depth in the secondary to contend with coordinator Bruce Arians' multiple receiver looks. San Francisco needs its cover men to hold up so Ss Mark Roman and Keith Lewis can lend a hand in trying to contain RB Willie Parker.
Key injuries: 49ers: WRs Arnaz Battle (groin) and Darrell Jackson (back) are expected to play, as are C Eric Heitmann (ankle) and S Michael Lewis (ribs). Steelers: OG Kendall Simmons (shoulder) will play.
FAST FACTS: The Steelers have outscored their first two opponents a combined 60-10. ... The 49ers are 2-0 for the first time since 1998. ... In 26 possessions, the 49ers have gained one or no first downs 21 times.
--LB Hannibal Navies could get the starting nod Sunday against the Steelers after Manny Lawson was lost for the season with a torn ACL. Navies started three games for the 49ers last season. He played sparingly on defense in the first two games, recording just one tackle.
--LB Brandon Moore might see some action at outside linebacker after the loss of Manny Lawson to a torn ACL. Moore played inside linebacker during training camp. Patrick Willis and Derek Smith beat him out for the starting job. Moore could play outside linebacker. He is used as a defensive end in nickel situations.
--LB Manny Lawson is out for the season with a torn ACL. He was tied for second on the team with 14 tackles through the first two games. Lawson is also adept at covering the tight end, a skill that will be missed on the 49ers defense.
--CB Nate Clements has gotten off to a strong start this season. He provided one of the big plays in the 49ers' victory over the Rams when he punched the ball out of the grasp of Rams receiver Torry Holt and through the end zone. In two games, Clements also has 12 tackles, one sack and broken up two passes.
--RB Frank Gore rejoined his teammates at practice after attending his mother's funeral early this week in Miami. He will play Sunday against the Steelers. Gore has 136 yards and three touchdowns on 38 carries in the first two games.
--WR Darrell Jackson did not return to practice Thursday, but said he will play Sunday against the Steelers despite an upper back sprain. Jackson sustained the injury in the first half last week against the Rams while executing a block. He leads the team with 97 yards receiving on seven catches.
--TE Matt Spaeth missed practice again Thursday with a bruised thigh and there's a chance he may not play Sunday. The rookie leads the team with two touchdown catches.
--G Kendall Simmons, who missed practice with a shoulder injury Wednesday, returned on Thursday and will start.
--RB Najeh Davenport, who plays on third downs and serves as Willie Parker's backup, returned to practice Thursday after missing Wednesday with a hamstring injury.
--LB Clark Haggans has been the most active of the Steelers' pass rushers through two games. He leads them with two sacks and also leads them with four quarterback pressures.
--PR Allen Rossum, acquired in a trade with Atlanta, has not beefed up the return game as the Steelers had hoped. He has four returns for 5.0-yard average and three fair catches on punts.
INSIDE THE CAMPS:
Outside linebacker Manny Lawson showed a remarkable improvement from his rookie season, as he was one of the 49ers' best players in the first two games. The 49ers received bad news Thursday when it was revealed that Lawson would miss the remainder of the season with a torn anterior cruciate ligament in his left knee.
Lawson was tied for second on the team with 14 tackles. He also had a pass defensed and one sack. He sustained the injury late in practice Wednesday.
"I was really looking forward to doing big things this year for my team, but the hardest things is just knowing I won't be able to be out there practicing and playing in games with the guys," said Lawson. "But, things happen for a reason and I will be back."
Coach Mike Nolan did not announce who will take Lawson's job in the starting lineup when the 49ers play the Steelers on Sunday. Veteran Hannibal Navies was listed as Lawson's backup on the depth chart. Parys Haralson and Brandon Moore could also see time at the strong outside position, Nolan said.
"I just have to pick up the slack," Navies said. "I'm looking at this as an opportunity to step in and play well."
Navies is a ninth-year player whom the 49ers signed last season after some injuries. Navies played in six games and started three. Originally, he was a fourth-round pick of the Panthers in 1999. He has also played for the Bengals and Packers in his career.
Lawson, a first-round pick from North Carolina State in 2006, is the second young 49ers player to be lost at that position this season.
Rookie Jay Moore was placed on injured reserve at the end of the exhibition season after sustaining a severe high ankle sprain.
The Steelers have stepped up the pressure on quarterbacks through two games, and the results are telling. They are tied for the NFL lead with 10 sacks and they've allowed an NFL-low 10 points.
It comes after Kevin Colbert, their director of football operations, declared in the spring that they needed a better pass rush after sacking quarterbacks just 39 times last season.
There's a logical explanation for the fast start: new coach Mike Tomlin has unleashed coordinator Dick LeBeau, who has cut the dogs loose. Former coach Bill Cowher held LeBeau back on some things he wanted to do, players say.
"I think we're a lot more active," safety Troy Polamalu said. "We're not as conservative. We're kind of initiating what the offense needs to do and not reacting to what they are doing."
The father of the 3-4 zone blitz, LeBeau has players rushing the quarterback from all over the field and the team's stats show it: Nine different players have participated in sacks, led by linebacker Clark Haggans' two.
"I wouldn't say it's a lot of different things," linebacker James Harrison said, "just putting people in different places than where they were before, moving them around and not seeing the same guy come every time."
"I think everybody's expected to be a pass rusher," Polamalu said.
Whether they can keep it up or not is another matter, but they already are more than one-quarter of the way to their 2006 total, which was tied for third lowest under Cowher.
Besides some different schemes, there are two notable changes in personnel on defense: James Harrison replaced departed Joey Porter at right outside linebacker and rookie LaMarr Woodley has played as a situational rusher.