Staley’s stay at the top of the football coaching profession proved to be brief as he was fired before the end of his third season as coach of the Los Angeles Chargers.

Staley took a couple of months of time off before resetting his coaching career in a lower-profile role as a defensive assistant for the San Francisco 49ers.

Staley welcomed the opportunity to work for a winning organization led by head coach Kyle Shanahan and general manager John Lynch even if it didn’t have the responsibility as the play-caller and coordinator.

“I don’t think looking at it as a reset is a bad thing,” Staley said Wednesday. “I was really excited about the role. There is a lot of common ground in how to lead a football team. This is what I was looking for more than anything, an opportunity where you feel you’ll be aligned with the right people who do things the right way and you have a chance to improve, and where you also have a chance to affect a team that can compete for a championship. All those stars kind of aligned and it’s been energizing.”

Staley has a bit of an amorphous role with an official title of assistant head coach/defense under first-time coordinator Nick Sorensen. He is bringing some fresh ideas to add tweaks to what has been one of the NFL’s top units in recent years, will work with the secondary bringing a few new wrinkles and use his experience of calling defensive plays for four years and being a head coach for three as a resource for Sorensen and Shanahan.

But Shanahan doesn’t anticipate any awkwardness with a staff that features a former coordinator of the NFL’s top-ranked defense working under a coach who has never called plays in the NFL.

“Nick knows who the defensive coordinator is, and Brandon does,” Shanahan said. ”Brandon is in a real good spot, just leaving from being a head coach and how he can help us in a number of roles. I think Nick feels very excited to have a guy on the staff who has called plays, who has done it at a number of different places and things. I think he’s helped him a lot in those ways. But no, there’s no really gray area of it.”

The 41-year-old Staley is viewed as one of the brighter defensive minds in the game even if his defenses didn’t play to that level during his three years running the Chargers.

Staley went from being coordinator at Division III John Carroll to being an outside linebackers coach under former 49ers defensive coordinator Vic Fangio in both Chicago and Denver for three years before being fired as defensive coordinator of the Los Angeles Rams in 2020.

He helped Los Angeles have the stingiest defense in the NFL in his one season with the Rams, leading to him getting the head coaching job for the Chargers.

Los Angeles fell a game shy of the playoffs his first season, got into the postseason as a wild-card in 2022 before blowing a 27-point lead to Jacksonville and then got fired with a 5-9 record last season.

The Chargers allowed the fifth most points, the third most yards per play and a staggering 210 plays of at least 20 yards the past three seasons.

“You take a deep look at all of it,” Staley said. “You have to unpack it the right way. You have to take time to do that, which I thought I did. You can’t do it yourself. You have to talk to a lot of different people who can help you. I read a lot. I worked out a lot. I was with my kids. Through all that, doing it the right way, it led me to an opportunity here where I was ready for it.”

Staley said he looks forward to working with Sorensen after getting positive reports on him from people who have worked with him in the past.

The Niners wanted someone well-versed in their defensive schemes to run the unit after struggling at times last year when Steve Wilks came in from the outside to replace DeMeco Ryans.

Ryans had also been an internal promotion when he got the job after Robert Saleh was hired as the New York Jets’ coach in 2021.

While Staley has typically used a more complex style of defense than the simpler approach that has worked well for the 49ers with a four-man pass rush and more zone coverages on the back end, he believes he can bring some subtle changes that can elevate the defense even more without compromising the core principles.

“They’ve always evolved,” Staley said. “I think since Kyle’s first season to now the defense has changed. … From Robert to DeMeco to Steve, and now Nick, I think you’ve seen a really nice evolution. That’s what’s important is that you don’t stray too far away from what makes you special. The style of play of this team is what’s made it special.”

The 49ers began their on-field work in the offseason with a surprise participant and a predictable absence.

Star pass rusher Nick Bosa took part in the voluntary portion of the offseason for a change after spending previous seasons working out on his own in Florida, while receiver Brandon Aiyuk remains away from the team as part of a contract dispute.

“It’s something that’s part of the business,” Shanahan said Tuesday about Aiyuk’s absence. “Anytime it’s part of the business part, you try to respect it. Stay out of as much as possible and look forward to the days when you can just focus on football.”

Bosa skipped last year’s voluntary workouts as he sought a new contract, and spent most of the 2021 and 2022 offseasons back home in Florida, after missing the 2021 offseason rehabilitating a knee injury and the 2020 offseason because of the pandemic.

Bosa said Shanahan called him earlier in the offseason to ask him to come to the voluntary practices this year after the Niners added several new linemen in free agency and hired a new coordinator in Nick Sorensen.

“I think it’s just good to get around the new guys,” Bosa said. “We have a lot of new faces this year. Just kind of helping the new guys out. I don’t think there’s really been much of a normal offseason for me in terms of we had COVID, we had my injury and the contract situation. It’s kind of a new year. I want to be around. It’s good to be around.”

Aiyuk is in a similar spot to where Bosa was last year when he was looking for a new contract that finally came following a lengthy holdout that ended just a few days before the start of the regular season.

Aiyuk is set to play on the fifth-year option worth about $14.1 million this season and wants a long-term contract that would pay him significantly more money based on his production so far in his career. Several of the top receivers have contracts in the $25 million a year range.

Aiyuk was a key part of San Francisco’s offense last season as he formed a great connection with quarterback Brock Purdy. Aiyuk had 75 catches and a career-high 1,375 yards last season with seven touchdowns as he earned second-team All-Pro honors.

Aiyuk has 269 catches for 3,931 yards and 25 TDs in four seasons since being drafted 25th overall in 2020, but has taken off since Purdy became quarterback.

“He’s a playmaker,” Purdy said. “I love throwing to him. Love BA as a person. It’s definitely important. But it’s out of my control. For me, I’m showing up every day trying to get better with the new guys and the guys that are here.”

Aiyuk wasn’t the only notable absence with All-Pro running back Christian McCaffrey, All-Pro left tackle Trent Williams and receiver Jauan Jennings among those not taking part in the practices this week. New defensive tackle Maliek Collins is also not on hand but does plan to join the team after his kids finish their school year.

Williams typically works out on his own in Texas during this portion of the offseason and Jennings can’t practice until he signs his restricted free agent tender. Shanahan gave no reason for why McCaffrey did not attend.

Several other key players aren’t taking part in on-field work as they recover from injuries or surgeries, including tight end George Kittle, cornerback Charvarius Ward, linebacker Dre Greenlaw, safety Talanoa Hufanga, center Jake Brendel and defensive end Drake Jackson.