Moore: Do Seahawks have their first below-average defense under Carroll?

Under Pete Carroll, the Seahawks have never had a below-average defense. But with the offseason departure of Frank Clark, six-game suspension of Jarran Reed and Tuesday’s injury to L.J. Collier, you have to wonder if that could change this year.

Notebook: Seahawks’ DL takes another hit with Collier’s injury

For the first six games, the Seahawks will be without a player who had 10.5 of the Seahawks 43 sacks last year. And Clark, who had 14 sacks last year, is now in Kansas City. With those two players, the Seahawks had an average pass rush. Without them?

It’s not like I expected Collier to be gangbusters this season. As spectacular as he’s become, Clark had only three sacks in his rookie season. I went back and looked at notes I wrote down about Collier after he was drafted and came across several that were promising such as favorable comparisons to Michael Bennett. But I also saw one that said he’s not a pure pass rusher.

His high ankle sprain, suffered during the first day of full pads, will likely keep him out of the entire preseason. Yes, he could be physically ready by the time the regular season starts, but how can you expect Collier to jump right in and be an impact player after missing valuable development time during training camp?

Yet to be honest, a lot would have been expected from him anyway as a first-round draft choice. Now I have a feeling he’ll be playing catch-up all season and we’ll be talking about Collier in the same way we talked about Rashaad Penny last year after he suffered an injury in training camp last year that set him back.

When I look at what the Seahawks have left on the defensive line, I see the Mariners’ bullpen: some guys with potential along with some retreads. You hope they’re going to pop, but there’s no one left that you can truly count on.

I like that they’re trying to see what they can get pass-rushing-wise from linebackers Barkevious Mingo and Shaquem Griffin. But again, we’re talking about hope with those two players. Second-year player Rasheem Green supplies more hope off of his strong performance in preseason games last year. Ziggy Ansah, the free-agent acquisition who starred in Detroit, should lead the team in sacks, but who knows how many games you’ll get from a guy coming off of shoulder surgery with a history of missing time because of injuries?

Cassius Marsh had 5.5 sacks for San Francisco last year, but a closer look shows that he wasn’t a consistently big factor in the 49ers’ pass rush. He had his sacks in three of the 16 games, including 2.5 against an Oakland team with a poor offensive line. Jacob Martin is one of the best bets to lead the Seahawks in sacks since he came on strong at the end of the 2018 season, but again it’s more about hope and potential.

Then at defensive tackle, you’ve got the veteran retreads in Earl Mitchell, Jamie Meder and Al Woods, who should be serviceable, along with Poona Ford, who should be the best player in the middle of the line. Rookie Demarcus Christmas has a cool name but is not likely to make the team.

Can you really expect that group to help improve a Seahawks run defense that allowed a whopping 4.9 yards a carry last year? Maybe so with a linebacking corps that should be one of the best in the league with Bobby Wagner, the return of K.J. Wright and Mychal Kendricks and the drafting of Cody Barton and Ben Burr-Kirven.

But behind them? There are questions about Shaquill Griffin at cornerback and the back end of the defense with Bradley McDougald ticketed to start at one safety spot, but who will start at the other? Lano Hill? DeShawn Shead? Marquise Blair? Someone else? You’re also missing one of the top nickel backs in the league in Justin Coleman, who signed a free-agent deal with the Lions. Whoever replaces him can’t be expected to play as well as Coleman; you just hope it’s not a huge difference.

Maybe this is oversimplifying the analysis of the whole situation, but if you’re missing a consistent pass rush, it exposes a secondary that no one is comparing to the Legion of Boom and looks to be mediocre now even if it gets dramatically better in years to come. I suspect that defensive coordinator Ken Norton will really have a tough job this year, looking for ways to prevent elite quarterbacks from carving up the Seahawks. I’d like to see them blitz more than they have in the past, but we all know that Carroll doesn’t like to bring an extra pass-rusher as much as other coaches.

The Seahawks will no doubt bolster their defensive line with an acquisition or two when players are released following the last preseason game, but then again, we’re talking about linemen like Mitchell, Meder and Woods who have experience and can certainly step in and play right away. But the expectations for any of them to shine is a longshot at best.

If the Seahawks are to duplicate their 10-6 record of a year ago and return to the playoffs, they will have to do it with a high-scoring offense compensating for a defense with too many weaknesses.