SANTA CLARA, Calif. — In the days after losing a low-scoring slugfest against the Los Angeles Rams, San Francisco 49ers defensive end Nick Bosa could finally see the light at the end of the tunnel.
Through the first 14 games under coordinator Nick Sorensen, the defense had been inconsistent. But that Dec. 12 matchup in which they had limited the Rams to 12 points and 4.6 yards per play left Bosa encouraged about the defense’s trajectory.
Bosa was so heartened by the defensive progress that he suggested Sorensen and much of the defense would and should remain the same in 2025, even going so far as to say “we have the right people in terms of coaches and players.”
But after the 49ers defense had been gouged for 38.7 points and 404.3 yards per game and came up with zero takeaways over the final three weeks, Bosa struck a different tone when asked about Sorensen.
“I think he’s a good coach,” Bosa said. “But it’s not my decision.”
Indeed, that decision fell to coach Kyle Shanahan, who provided multiple votes of confidence for Sorensen throughout the season. But the defensive regression over the final three weeks left Shanahan ready to move on from Sorensen.
Now the the team is searching for its fourth defensive coordinator in as many years. Of the previous three, only DeMeco Ryans held the job for more than one season before he became the head coach of the Houston Texans. Steve Wilks was one and done after the 49ers made the Super Bowl last season. Unlike Wilks, Shanahan would like to retain Sorensen in a different role.
According to Shanahan, the choice to move on was as much about the options available as it was the defense’s 2024 performance. Unlike the past two years when the Niners had advanced deep into the playoffs and many of the top potential coordinators had already been hired elsewhere, they’re on equal footing with the opportunity to hire just about any of the available options this time around.
“It was a real tough decision,” Shanahan said. “I love Nick as a person and I love him as a coach… But just where we’re at, really as a team, where I think we need to go. There are a lot of big decisions ahead for us. And as hard as it is for me to come to this conclusion, I feel there are some options out there that can end up being a better option in the situation that we’re in for our team.”
That many candidates come with experience in the job is appealing to Shanahan. He turned to Sorensen because of his familiarity with the 4-3 scheme that Shanahan prefers, but also had never been a defensive coordinator before.
This year’s crop of candidates includes coaches who check both boxes. Headlining that list is Robert Saleh, who held the 49ers coordinator post from 2017-2020 before becoming the New York Jets head coach.
Saleh runs Shanahan’s preferred scheme, knows the key defensive leaders still on the roster and has proved adept at altering the defense when injuries or other factors have made it necessary. He interviewed for the job on Thursday and a reunion is possible, if not likely.
The complicating factor with Saleh is that he has head coaching interviews lined up with the Jacksonville Jaguars and Las Vegas Raiders. If he emerges as a top candidate for either job and those searches drag on, it will make it difficult for Shanahan and the Niners to wait as other coaches are hired.
Jeff Ulbrich, who replaced Saleh as the interim coach of the Jets and whom the Niners attempted to hire last year, could also be available depending on how things play out in New York. Ulbrich is a San Jose native who played linebacker for the 49ers for 10 years and also runs the scheme Shanahan prefers.
While Saleh and Ulbrich are considered top candidates, another name worth keeping a close eye on is former New Orleans Saints coach Dennis Allen. Allen has extensive experience, working eight years as a defensive coordinator in Denver and New Orleans, almost six seasons as a head coach with the Saints and Raiders and another year as the Saints senior defensive assistant.
Shanahan has long respected Allen, as most recently evident in the fits Allen’s defense gave Shanahan’s offense in a Nov. 2022 victory in which the 49ers managed just 13 points on 4.7 yards per play against Allen’s Saints.
New Orleans fired Allen this season with eight games left but he has another year on his contract, which means he could take the year off to regroup while still being paid if he wanted to.
But on an appearance on the “Unbreakable with Jay Glazer” podcast, Allen indicated he will have opportunities to continue coaching and would likely pursue those. Allen has been linked to the Indianapolis Colts’ defensive coordinator vacancy and is considered a possibility to be Ben Johnson’s defensive coordinator should he take a head coaching job somewhere. That means the Niners would have competition for Allen’s services if they want to pursue him.
Brandon Staley, who joined the 49ers as assistant head coach last offseason, is the only known in-house candidate. Shanahan said he plans to interview Staley again. Among the other well-known names who have experience and could draw interest: former Indianapolis Colts coordinator Gus Bradley, former Cincinnati Bengals defensive coordinator Lou Anarumo and Raiders defensive coordinator Patrick Graham (if he becomes available). Detroit Lions defensive passing game coordinator Deshea Townsend has also interviewed already.
I think having the experience of going through this before, building things before, I think is definitely a bonus for me,” Shanahan said. “It helps me with some stuff… But again, you don’t want to put just any handcuffs on your decision. You’re going to always try to figure out the best one. So, you’ve got ideas going into that but just being so early I’m going to have an opportunity to talk to a number of guys too, so we’ll see what that leads us to.”
One of the biggest questions in this search is whether Shanahan strays from the defensive principles he’s favored since he took over in 2017. That includes heavy doses of zone coverage, infrequent blitzing and mostly four-man fronts.
Since 2017, the 49ers have played zone coverage on 61.2% of opponent drop backs, the highest rate in the league. Along with that, they’ve blitzed at the fifth-lowest rate in the NFL (22.4%).
While Shanahan has been loyal to that scheme in recent coordinator searches, he is more open-minded this time around, which could open the door for someone like Staley, a Vic Fangio disciple who prefers more multiple looks, to make a push for the job.
More than anything, though, the defensive struggles in 2024 showed Shanahan that whoever his next coordinator is needs to have the ability to adapt when injuries or other issues take hold.
“I love the scheme that we’ve had here,” Shanahan said. “I think it’s one of the hardest things to go to when you’ve got the right guys in the right spots… I’m not saying you’ve got to change schemes, but you have to have the ability, the history and the knowledge of how to change some stuff up when you’re in some certain situations. And I think that we do need that more going forward.”
