SANTA CLARA, Calif. — With a quarterback to pay, more than a dozen pending free agents and an aging nucleus, the San Francisco 49ers entered the 2025 offseason with plenty of uncertainty. But there was one move they knew they wanted to make above all others: bring Robert Saleh back for a second stint as defensive coordinator.

“Whether we played with a bunch of young guys, old guys, I wanted Robert Saleh on our staff,” general manager John Lynch said. “We were in pursuit of Robert as soon as we knew that was a viable option.”

That pursuit didn’t come sans drama. The New York Jets had fired Saleh as coach five games into the 2024 season, and he went on to spend the final weeks of the campaign as a consultant for the Green Bay Packers. But when the season was over, Saleh had no shortage of suitors for his services — whether as a potential head coach or as a coordinator.

On Jan. 7, the Niners fired Nick Sorensen after one season as their defensive coordinator. They immediately reached out to Saleh, who ran their defense from 2017 to 2020. During initial discussions, they made it clear they were willing to make Saleh one of the highest-paid defensive coordinators in the NFL and that they didn’t want anyone else for the job.

In the ensuing 17 days, Lynch and 49ers coach Kyle Shanahan anxiously waited for Saleh to sort through his options. There were head coaching interviews with the Dallas Cowboys, the Las Vegas Raiders and the Jacksonville Jaguars.

According to league sources familiar with the discussions, Saleh was the perceived leader in Jacksonville for about 24 hours before Liam Coen opted to take the job after initially declining. Saleh also was a finalist for the Raiders’ coaching job then rejected an offer to be the Raiders’ defensive coordinator and the eventual successor to coach Pete Carroll. Saleh finally reunited with the Niners on Jan. 24.

Saleh told ESPN recently that he was “always” going to return to San Francisco unless he got a head coaching job.

“He was definitely our first choice; we were hoping that we would be his, and that’s what he told me early on,” Shanahan said. “I was glad he stuck with his word or we would’ve had beef.”

Saleh has rewarded the Niners’ patience with his blend of energy, familiar but evolving scheme and player-friendly messaging. He has their patchwork defense — which lost star veterans Nick Bosa and Fred Warner early in the season — staying afloat in the face of adversity and straining to exceed the sum of its parts. A win Monday night (8:15 p.m. ET, ESPN/ABC) at the Indianapolis Colts would clinch a playoff spot for San Francisco and shine further light on Saleh’s candidacy for another head coaching opportunity. And some coaches around the league already believe he will get another shot — if he wants it.

Saleh knew nothing would come easy upon his return to San Francisco. The 49ers quickly told him of the plan for a dramatic roster reset that saw the departure of such defensive stalwarts as linebacker Dre Greenlaw, cornerback Charvarius Ward and safety Talanoa Hufanga, along with other veterans.

What nobody could have prepared for is the position Saleh and the defense are in because of the season-ending injuries to Bosa (knee) and Warner (ankle), the defense’s two best and most important players.

Beyond Bosa and Warner, the 49ers have played large chunks of the season without first-round rookie lineman Mykel Williams, versatile defensive lineman Yetur Gross-Matos and safety Malik Mustapha because of knee injuries. Middle linebacker has been hit so hard that five players have taken at least 20 snaps there.

Still, Saleh’s unit of mostly unproven young players and journeymen veterans is 11th in the NFL in points allowed (20.9) despite ranking in the bottom half of the league in nearly every other major defensive category.

The work Saleh has done with this group could have better positioned him to get another head coaching opportunity as soon as the offseason.

“Everyone wants to be at the top of their profession, and they want to succeed at that just to see how far they can go and what they can achieve,” Saleh told ESPN. “Is my desire to get to the top of the profession and hoist the Lombardi one day? Absolutely. Am I in a hurry? No, I love it here.

“Obviously, the desire is there, but at the same time, it’s not desperation.”

MORE THAN A YEAR removed from the end of his three-plus-year tenure leading the Jets, the perspective gained from that experience is never far from Saleh’s mind.

At various points in an average week, Saleh can be found in his office providing a different view of the game tape to safety Ji’Ayir Brown, offering encouragement and belief to backup cornerback Chase Lucas, engaging in specific scheme conversations with safety Jason Pinnock or enjoying cookies with tight end George Kittle.

Before he took the job in New York, Saleh spent almost two decades working only with the defense. Suddenly, he had to connect with an entire team, not to mention the support staff in the building. It wasn’t until his second season with the Jets that Saleh says he prioritized connecting with anyone and everyone in his orbit.

“Being a head coach did help me understand that,” Saleh said. “I do think it’s important anytime you can connect with anyone in the building.”

Saleh is back to coaching just defense with the 49ers, but he still wants to be a resource for everyone in the 49ers’ facility.

“I think his understanding of offensive players and just kind of what we go through has opened up his understanding of being a football coach,” Kittle said. “I just think he’s grown as a coach.”

Spending time in the top job allowed Saleh to gain a greater understanding and respect for what other head coaches go through. Saleh and Shanahan have remained close, but their understanding of each other has evolved because of their shared head coaching experiences.

Saleh also can help with the unspoken challenges of that burden, which is why he makes it a point to check in on Shanahan during the week, especially when problems — such as a rash of injuries — arise.

“Being the head coach is lonely,” Saleh said. “I try not to be too invasive but just being a helping hand when he needs me. I can kind of feel when he feels like he has the world on his shoulders, where he’s got the entire organization on his back and he just kind of needs a buddy to hang out with at lunch.”

AS ONE OF the few players in the Niners’ locker room to play for Saleh the head coach and Saleh the coordinator, Pinnock might best understand how Saleh has managed to squeeze the most out of this 49ers defense.

When Saleh returned in January, he brought his old mantras back with him. At his first news conference in May, Saleh wore a black bracelet inscribed with the motto “All Gas, No Brake” in white letters.

As the offseason program progressed, his players began hearing an offshoot of that phrase boiled down to one word: strain. The concept isn’t complicated. It’s an emphasis on playing as hard as possible for as long as possible and never giving up on a play, a drive or a game. Lest it be forgotten when there were no games, the Niners crowned a weekly “King of Strain” during offseason workouts.

Winning that prize — a T-shirt with a side of bragging rights — is achieved by accumulating points from things such as how many one-on-one snaps you can win, weight lifting reps relative to body weight, attempts to rake the ball away in practice, linebackers executing “peanut punches” and anything that involves playing through the echo of the whistle.

During the season, strain is measured more in teamwide evaluations such as how many helmets are in the picture when game tape is paused at the end of a play, a sign that everyone on defense is running full speed to the ball at all times.

For the first few months of Saleh’s return, Pinnock and other Niners said they would hear the word from him or other coaches “hundreds” of times during a week. That has lessened as the season has gone on, a sign that the message has been received and absorbed.

“At some point, that’s who you are,” Pinnock said. “That’s what you do.”

Effort is the baseline for every defense, but for these Niners, it’s the secret sauce that has kept them afloat when so many things have gone awry. It’s been evident in many of their 10 victories this season.

Absent the dominant pass rush that was the hallmark of Saleh’s first stint in San Francisco — the Niners rank last in the NFL in sacks (16) and pressure percentage (23.2), and they sit 31st in pass rush win rate (29%) — the 49ers have leaned heavily into eliminating explosive plays.

To that end, Saleh has continued to adapt his scheme. He has skewed away from rushing four and playing Cover 3 behind it, opting to play Cover 4 at the second-highest rate in the NFL (22.4% of snaps) and with two-high safeties the sixth most in the league (50.9%). (In 2019, Saleh’s Niners played Cover 4 on 17.4% of opponent dropbacks, with two-high safeties on 37.8% of snaps.)

The idea is to force opposing offenses to execute long drives where more snaps increase the possibilities of a mistake. San Francisco has allowed the fourth-fewest explosive plays (passes of 20-plus yards or rushes of 10-plus yards) in the league.

“When you start missing the type of players we are, you’ve got to come up with different ways to win,” Lucas said. “I think he’s done a tremendous job with that.”

That approach explains why some of the biggest plays of the 49ers’ season have taken place in the shadow of San Francisco’s end zone.

In Week 5 at the Los Angeles Rams, rookie defensive tackle Alfred Collins‘ forced fumble and recovery at the goal line late in the fourth quarter and a fourth-down stop at the 11-yard line in overtime sealed the Niners’ biggest victory of the season. In a Week 11 win at the Arizona Cardinals, rookie cornerback Upton Stout forced another fourth-quarter fumble at the 1-yard line to stamp out a potential Cards comeback. The next week against the visiting Carolina Panthers, Brown intercepted Bryce Young‘s pass in the end zone to preserve an early San Francisco lead. The Niners’ defense has added 0.99 points of win probability in the red zone, best in the NFL.

The 49ers’ four takeaways inside their 20-yard line are tied for second most in the league. And their goal-to-go defense is eighth best in the NFL, giving up a touchdown on 68.2% of drives inside their 10.

None of Saleh’s players believes that is by accident.

“That relentless strain and effort and finish, those are all things that just define the character of our defense and our team,” Stout said. “Everybody in the building from the head coach to the coordinator to the GM, we want to be defined by our grit.”

WITH THE 49ERS on the verge of returning to the NFC playoffs, Saleh isn’t worried about what is next for him.

Two head coaching jobs — the Tennessee Titans‘ and the New York Giants‘ — are already available with four or five more potentially opening. Saleh is expected to draw plenty of interest.

“I think he will get interviews and be considered a strong candidate,” a league source said. “[It’s a] weak candidate pool. He has credentials and done a good job with an injured defense.”

A veteran NFL coach said Saleh should be helped by good relationships with offensive coordinator candidates from the Shanahan tree — such as Niners coordinator Klay Kubiak, Rams coordinator Mike LaFleur and, potentially, Miami Dolphins coach Mike McDaniel (if he is fired at the end of the season) — to bring with him.

Another veteran coach said Saleh’s tenure in New York should age better than his 20-36 record there might indicate. In 2021, Saleh took over a two-win team and proceeded to win seven games in each of 2022 and 2023 with the likes of Zach Wilson, Mike White, Brett Rypien and Trevor Siemian starting games at quarterback.

The franchise’s regression under current coach Aaron Glenn (with a 3-12 record) this season only offers further proof of how difficult it is to win with the Jets, that same veteran coach said.

“It showed what Robert had to overcome and that it wasn’t easy,” the coach said.

While it would be reasonable for Saleh to fear that his Jets tenure could work against him in the pursuit of another head coaching job, history has been surprisingly kind to coaches with similar profiles.

Since 2001, the Jets, who haven’t been to the postseason since 2010, have hired six head coaches who arrived in New York with a defensive background. That list includes Saleh, Herm Edwards, Eric Mangini, Rex Ryan, Todd Bowles and Glenn. Ryan, Edwards and Mangini all got a second head coaching job within a year of being fired by the Jets. Bowles had to wait four years but took over the Tampa Bay Buccaneers in 2022.

Still, Saleh will likely have to explain his record in New York if and when he goes back on the interview circuit this offseason. Beyond the lessons he learned from his time with the Jets, Saleh also will seek the delicate balance between striking while his name is hot and being discerning for the right opportunity.

For his part, Saleh said he intends to lean on Shanahan and Shanahan’s father, Mike, along with other close coaching friends for advice this time around.

“We didn’t do a good enough job and the owner decided that it was time to move on, and so that’s what it is,” Saleh said of his exit from the Jets. “That’s where I’ve got to look inward and see what we could have done better, and those are the things that I’ve been trying to learn from those experiences so if that opportunity presents itself again, I’ll be more prepared.”

According to Saleh, he and Shanahan didn’t really discuss how long his second stint in San Francisco might last.

The Niners would love to get at least one more year from Saleh, not only to see what he could do with another offseason of roster tweaks and a healthy Bosa and Warner but also because they could gain two more compensatory picks if Saleh takes another head coaching job thereafter.

Kittle, who has said repeatedly that Saleh was San Francisco’s biggest offseason addition, half-jokingly suggests he needs to stop talking Saleh up so Saleh will stick around longer.

It’s a sentiment shared by Shanahan, who also knows there’s a real chance he will be hiring a fifth defensive coordinator in as many years this offseason. His hope is that it comes as a result of Saleh’s defense contributing to another deep — and perhaps unexpected — postseason run.

“I hope for us he’s not a head coach next year,” Shanahan said. “But I also know when you have the talent that someone like Robert does, it’s only a matter of time.”

ESPN’s Jeremy Fowler contributed to this story.