SEATTLE — Amid the record-setting roar from the crowd and the delay-inducing lightning and thunder Sunday night, Cliff Avril finally made a little noise of his own.
Avril was one of two prize free agents signed by the Seahawks in the offseason, with Michael Bennett the other. Each was brought in to help a pass rush that proved problematic down the stretch of the 2012 season.
Sunday, during the 29-3 rout of San Francisco, the Seahawks were able to see for the first time what their investment of $18 million looks like on the field. (Avril signed a two-year deal worth $13 million, Bennett signed for one year and $5 million.)
And Monday, coach Pete Carroll needed just one word to describe how it made him feel: “Thrilled.’’
Avril and Bennett sparked a defensive front that harassed San Francisco quarterback Colin Kaepernick all night, sacking him three times, and also put a harness on the 49ers’ running game. San Francisco rushed for 100 yards, but 87 came on scrambles by Kaepernick. San Francisco’s running backs managed just 13 yards on 11 carries, including only 16 on nine from Frank Gore.
“We were physically up for the challenge,’’ Carroll said. “I think we played the line of scrimmage great. The defense was on it.’’
Avril, who missed the opener against Carolina with a hamstring injury, and Bennett each had sacks. Avril’s sack forced a fumble late in the second quarter to set up a Seattle field goal.
“Michael Bennett has done a nice job, been such a factor,’’ said Carroll. “It’s great that Cliff finally gets a chance to play and he was really a factor early and really had a chance to get three sacks in the game. Cool to see that happen right off the bat.’’
In fact, it was missed sacks that seemed foremost on Bennett’s mind after the game.
“I missed two by myself, Cliff missed one, (defensive end) Red (Bryant) missed two,’’ he said. “We should’ve had a nine-sack night. But those things happen and you know we’ve got to get better at that. But we pushed good tonight.”
That was the plan when Seattle signed Bennett and Avril. Bennett began his career with Seattle as an undrafted free agent in 2009 before being released and becoming a starter with Tampa Bay, where he spent the past four seasons. Avril became known as one of the best pass rushers in the league the past five years in Detroit, with 39.5 sacks.
Avril gave most of the credit Sunday to the secondary, saying, “They allowed us to rush, made him (Kaepernick) hold the ball a little longer than usual, and we got after him a little bit.’’
Still, the performance of the line was hard to ignore, serving as yet another reason for optimism in a season dripping with it.
Seattle is still without end Chris Clemons, who led the team in sacks last year with 11.5, and Bruce Irvin, who had eight.
Clemons is recovering from a knee injury and could return this week against Jacksonville, Carroll said Monday. If not, Clemons will almost certainly play the following week at Houston.
Irvin is sitting out the first four games while suspended for violating the league’s policy on performance-enhancing drugs.
• Carroll said left tackle Russell Okung is almost certainly out for the game Sunday against Jacksonville after injuring his toe against the 49ers. Otherwise, though, Carroll offered few specifics about an injury that could be critical if it proves to be long-term.
Carroll said of Okung’s injury, “There’s a little bit of a spectrum’’ of how serious it could be and how long he could be out. ESPN reported that Okung had a torn ligament but Carroll did not confirm that, saying, “We are still digging for information. … I know there’s some stuff that happened there and we are waiting to figure it out. If I told you something I’d be making it up.’’
Carroll also was vague on whether the plan would be to again go with Paul McQuistan at left tackle, as was the case Sunday when Okung went down. Another possibility could be rookie Alvin Bailey, who is listed as Okung’s backup, though he has yet to play.
• The only other injury of note Sunday was suffered by fullback Spencer Ware, who suffered a “significant’’ ankle sprain on the final offensive play of the game, Carroll said. It’s unclear how long he might be out.
• Carroll also said cornerback Brandon Browner is expected to return to practice Wednesday “with the intent to play’’ against the Jaguars. Browner has missed the first two games with a hamstring injury.