EL SEGUNDO — Chris O’Leary’s feet were firmly planted in Kalamazoo, Michigan, for the 2025 season, after leaving the Chargers and taking the job as the defensive coordinator at Western Michigan. His head and his heart were there, too, but there was something about Southern California that called out to him.

So, on every Wednesday last season, when his work with the Broncos was done, he would review the video of the Chargers’ latest game, preparing the highlights to be shown to his players at Western Michigan. He would tag specific plays, alter the terminology slightly and show them to his players.

O’Leary would then deliver a short message.

“Watch the guys at the highest level do it,” he recalled telling the Broncos.

O’Leary spent all of one season at Western Michigan, returning to the Chargers as their defensive coordinator last week, after Jesse Minter departed on Jan. 22 to become the head coach of the Baltimore Ravens. O’Leary had Minter’s full endorsement and the hiring process was swift.

In many ways, O’Leary and Minter had been joined at the hip for years. Their association began when O’Leary was a scout team quarterback and later a wide receiver at Indiana State, where Minter was coaching with his father, Rick. They teamed up again at Georgia State, this time with O’Leary as a graduate assistant coach working with the defensive line.

What did he know about the D-line?

Not much, as it turned out.

But “I fell in love with defense,” O’Leary said.

What’s more, it didn’t prevent them from being reunited later at Florida Tech and then, after O’Leary spent six seasons at Notre Dame, with the Chargers as part of head coach Jim Harbaugh’s staff after his hiring before the 2024 season. O’Leary coached the safeties, helping to establish the NFL’s stingiest defense.

Last season, O’Leary’s defense helped Western Michigan win the Mid-American Conference championship with a 10-4 record. The Broncos’ defense gave up an average of 17.4 points per game, ninth-best in FBS and second-best in the MAC. The way it ended was better than how it started, though.

“I think three of the first four drives against Michigan State we gave up touchdowns,” O’Leary said, recalling a less-than-stellar start to his tenure as defensive coordinator at Western Michigan this past season, an eventual 23-6 loss on Aug. 29 at East Lansing. “So, that was a wake-up call.”

Western Michigan lost its next two, but closed with a 10-1 flourish.

Minter’s departure, which Harbaugh and General Manager Joe Hortiz anticipated, opened the door for O’Leary’s return. O’Leary said he had other offers, but coming back to the Chargers was “a no-brainer.” Coaches and players reached out immediately, especially Pro Bowl safety Derwin James Jr.

“I think he called during the interview,” O’Leary said, laughing.

Now comes the tough part. Now he must find a way to make one of the NFL’s top defenses even better. The Chargers were the NFL’s ninth-best defense this past season, giving up an average of 20 points per game, sparking the team to its second consecutive 11-win season.

“There are two things we’re going to focus on,” O’Leary said. “Number one, we’re going to elevate what we do well. The foundation of our defense, we’re going to elevate that. We’re going to do what we do and do it better. The second thing we’re going to do is evolve the defense. We’re going to add things. We’re going to tailor things to the players, the personnel we have going into the season.

“We’re going to focus on what we’ve built, the foundation that’s been laid, and take it to another level.”

O’Leary merely laughed when asked if he had reached out to standout outside linebackers Khalil Mack and Odafe Oweh, two pending unrestricted free agents, to urge them to come back to the Chargers next season. Clearly, it was a question and a job for Hortiz in the coming weeks.

Free agency opens March 11.

“I think all the guys here see me as a coach, see me as a guy who’s going to push them and really pull the most out of them,” O’Leary said. “When I left Western Michigan, I cried like a baby when I was talking to the players because you invest so much in them. They want a coach who loves them, respects them as a person, who wants what’s best for them and, ultimately, makes them better.”