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With Kwon Alexander gone, how worried should you be about 49ers’ youth at linebacker?

© Stan Szeto-USA TODAY Sports

For the past four-to-six weeks, key injuries have done nothing to disrupt the methodical drum beat of the 49ers’ still undefeated season. Without Joe Staley, Mike McGlinchey, Kyle Juszczyk and Ahkello Witherspoon, little-known backups demonstrated starter-level capabilities and kept San Francisco comfortably afloat.

It almost felt like there was no injury this team couldn’t weather. Then, Kwon Alexander tore his pectoral muscle. He’s out for the season.

For as successful as the 49ers have been at replacing key injuries during the year, none—outside of the preseason—have been season-ending, and none of them have been at a position so individually crucial to offensive or defensive schemes like Alexander’s is.

Juszczyk was the only other injury of similar concern, in that he provides so much creativity, both as a blocker and pass-catcher, in a way that couldn’t be replaced. Ross Dwelley performed admirably in Juszczyk’s stead, but to pretend he was anything more than serviceable would be kidding yourself.

If you had to crown a defensive MVP for the 49ers, it would almost certainly be Nick Bosa. But the runner-up? There’s a strong argument to be made it’s Alexander.

His speed, tracking and tackling efficiency in combination with Fred Warner’s has allowed the 49ers to successfully increase their use of nickel packages. Off the field, his impact has been similarly seismic.

He’s brought out the best not just in Warner—effectively encouraging increased aggression and vocality—but in the entire defense. He created the “Hot Boyzz” title to bring unity and confidence to a young linebacking group, which, outside of Alexander and Mark Nzeocha, features only first- and second-year players (the third-year Elijah Lee is on the practice squad along with rookie Demetrius Flannigan-Fowles).

Alexander’s season ends with him as the team’s second-leading tackler (34 combined tackles). His three quarterback pressures are the highest on the team for a non-defensive lineman. His coverage abilities, though, will be his most sorely missed asset. He’s allowed just 4.1 yards per target and a 52.5 passer rating when targeted and has taken much of the burden (and potential blame) off Warner’s shoulders.

That tandem of speed and range, along with the capable tackling of nickel corner K’Waun Williams, gave Robert Saleh that comfortability to switch from a 4-3 base scheme to mainly nickel.

“Having Fred [Warner] and Kwon Alexander in there always will give you that flexibility where you’re not as nervous to play your coverages,” Saleh said ahead of the 49ers’ win over the Carolina Panthers.

Now, it’ll be Warner and fifth-round rookie linebacker Dre Greenlaw tasked with holding down the middle of the field and supporting the defensive line. When Saleh does go with 4-3 looks, it’ll be Azeez Al-Shaair, another rookie, but an undrafted one, as the strong side SAM linebacker.

Greenlaw played four years at Arkansas, missing five games with a foot injury in his sophomore season and missing three in his senior season before being taken by the 49ers with the 148th overall pick in the 2019 NFL Draft. Al-Shaair would have likely been drafted had he not torn his his meniscus and ACL (as well as a minor, grade one MCL injury) in his senior season at Florida Atlantic University.

Both Greenlaw and Al-Shaair were consistently impressive in the preseason, with Greenlaw winning that starting SAM job and Al-Shaair making the roster over the likes of veterans David Mayo, LaRoy Reynolds and Malcolm Smith.

Al-Shaair had 13 tackles, one pass breakup and a fumble recovery along with impressive special teams displays in the preseason. Greenlaw, who had proven his capability on the practice field, demonstrated speed and a knack for making key tackles, getting into the backfield and stopping the first play of team drills on multiple days in a row.

“He’s a very instinctive player, sometimes too instinctive,” said Warner of Greenlaw during training camp. “He’s still got some things he’s got to clean up, but… I know he’s going to make plays when he’s out there, and I think he’s going to play in this league for a long time.”

Greenlaw played nearly a full game in the season opener against the Tampa Bay Buccaneers after Alexander was ejected for a helmet-to-helmet hit on Jameis Winston. Greenlaw finished with four tackles and was given a good-but-could-be-better review from Saleh.

“I think Greenlaw did some good things. He’s definitely a good tackler, he’s not afraid to hit you,” Saleh said. “It was good for him to get that experience and to come away with a win, which is similar to even Tarvarius [Moore] who was like that. Tarvarius planned on being out there that long, so Greenlaw was a little surprise. That’s the NFL. You only have five guys up, especially with [LB Mark] Nzeocha focusing mainly on special teams. Once we lost Kwon, it was a chain reaction to everybody, so he had to step it up. He had to play a lot. Had a few rookie mistakes like they all do, but he played good enough for us to win and I was happy with him. Now, we need to get better going forward.”

Saleh was more tight-lipped about Al-Shaair heading into the season. While he made the final 53-man roster, it appeared to be part truth and part tactical in the sense that the 49ers clearly wanted to keep him on the team, and by hushing any public praise for him, they could potentially sneak him on to the practice squad if need be.

His first assessment of Al-Shaair, on August 13, was that the coming to weeks “are going to be big for him in terms of proving that the league’s not too big for him. Still trying to make sure that we get a good evaluation on him before we speak up.”

Al-Shaair continued that progress, but was given a similar semi-pessimistic assessment by Saleh that he needed to learn heaps of information.

“I still feel the same. He’s undrafted, he didn’t get OTAs, so he’s still behind mentally in terms of playbook stuff—I shouldn’t say behind. He’s still playing catch-up,” Saleh said. “There’s still subtle nuances and details that come into that MIKE linebacker spot. I have a process that players should go through, you get your call, you get your alignment, you get your key, which is you place your eyes where they need to be and you execute the defense.

He’s still catching up to the alignment part, and if you’re still trying to play catch-up to alignment, you’re going to be playing catch-up with your keys, which leads you to play catch-up with your execution. When he’s aligned, his eyes are right and all that stuff, he looks pretty good, but there’s still a lot of things with regards to the many different looks, plays, formations that offenses can give him with regards to all the different defenses we run where he needs to get on it from a precision standpoint to be able to take his game to another level.”

While Saleh tends to puts a damper on praise for young players, especially rookies, those criticisms were genuine. He was sharing more of the negative, youth-oriented criticisms, while keeping most of his optimistic predictions to himself in order to protect those players, but he wasn’t making up the flaws he observed.

Both Greenlaw and Al-Shaair are far more familiar with Saleh’s defensive schemes than they were at the start of the season, but they’re still rookies with a severe lack of experience. They both play positions—especially Greenlaw—which demand making pre-snap identifications and on-the-fly decisions.

While Warner has demonstrated he’s more than comfortable with his role as the MIKE linebacker, and assisting the rest of the defense with those identifications, he had the experienced Alexander beside him, capable of making those same reads and plays with top-tier speed. The 49ers might survive without Alexander, but it’s an issue that might well be exposed by opposing offenses.


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