DENVER >> Jack Del Rio’s stock is soaring less than two years after his firing in Jacksonville.

The Broncos confirmed Sunday that Del Rio interviewed for the head coaching job at Southern California during Denver’s bye week. Fox Sports first reported Del Rio’s interview with his alma mater.

USC athletic director Pat Haden reached out to Broncos executive vice president John Elway for permission to speak with Denver’s defensive coordinator at a time that was convenient for the NFL team.

Del Rio is leading the Super Bowl-or-bust Denver Broncos while John Fox recovers from heart surgery.

Within three months, Del Rio figures to have a spacious office on a college campus or at an NFL complex.

Del Rio was handed a golden opportunity to basically audition for any number of head coaching jobs when Fox landed in a Charlotte, N.C., hospital two weeks ago and his doctors determined he could no longer put off an operation to replace his defective aortic valve that wasn’t pumping enough blood throughout his body.

Del Rio was named interim head coach of Broncos 48 hours later and he immediately decided to keep his defensive coordinator duties, as well.

Del Rio, who went 69-72 in 8 1/2 seasons as Jacksonville’s head coach from 2003-11, never had a quarterback with the Jaguars like he does in Denver in Peyton Manning.

And even though he came from a defensive background built on his 11-year pro career as a star linebacker, Del Rio never had a defense with the Jaguars like the one he leads in Denver with the likes of Von Miller, Wesley Woodyard, Dominique Rodgers-Cromartie and Champ Bailey.

Although Del Rio and Fox go way back — Fox hired him as his first defensive coordinator when he got his first head coaching job with the Carolina Panthers in 2002 — Del Rio is not a carbon copy of Fox.

He told The Associated Press recently that he isn’t just channeling Fox during this stretch of games while his boss recovers.

“You could characterize it how you’d like. I’ve said very clearly, he’s established a blueprint and I’ve worked with him before. So, I understand John,” Del Rio said. “I also understand myself, having been a head coach for nine years. I can’t possibly be at my best if I’m going to stop and pause and go, ‘What would John do? Oh, uhhh.’ No, I can’t do that.”

The Broncos were impressed by Haden’s approach because college administrators are under no obligation to seek permission from NFL teams before reaching out to their coaches. Haden is a former NFL quarterback.

Del Rio interviewed for the Trojans’ job Nov. 1. The next day, Fox fell ill while golfing in North Carolina and his doctors moved up his scheduled heart surgery to Nov. 4, the same day Del Rio got the interim head coaching tag.

Del Rio is the first known candidate to have interviewed for the USC job. Haden been secretive about the process.

“I can honestly say that was handled the proper way,” Del Rio said after Denver’s 27-17 win over the previously unbeaten Kansas City Chiefs on Sunday night that left both AFC West teams at 9-1. “They contacted the Broncos, got permission, and we did it in a manner where they came out here and visited with me during our bye week so it wouldn’t disrupt anything.

“That’s what took place. Now, my job continues. My focus is here. It’s an honor to be in consideration for something like that, but I also feel very honored to be here and be the defensive coordinator and interim head coach for the Denver Broncos. All of my attention, all of my efforts and energies are going into the Denver Broncos right now.

“Down the road who knows where that goes? But that’s certainly not anything that needs to be discussed other than, is it true? Yes. It did occur. But that’s really it. I’m acknowledging it absolutely did, it was handled in a professional manner and now my attention is completely with helping this football team be prepared.”

Before Sunday, Del Rio had steadfastly declined to publicly discuss any possible interest he might have in returning to USC, where he starred as a linebacker in the early 1980s, earned consensus All-America honors as a senior and was named co-MVP of the 1985 Rose Bowl.

USC fired Lane Kiffin earlier this season and Ed Orgeron returned fun to a dour program — and wins, none bigger than a 20-17 win over powerful Stanford on Saturday night. It was Orgeron’s fifth win since stepping in for Kiffin in late September.

One thing’s for sure: Del Rio isn’t going anywhere before the Broncos’ season is over.

Del Rio could be busy coaching the Broncos into February. Cardiologists and heart surgeons say recovery from aortic valve replacement and its arduous cardio rehab can take anywhere from a few weeks to a few months.

If the Trojans and Del Rio want each other — and neither party has indicated that, at least publicly, so far — USC would have to wait for him to fulfill his contractual obligations to the Broncos, which expire after the Super Bowl.

It’s also important to remember that Del Rio has spent 28 seasons in the NFL altogether. And if the Broncos do well under his watch, there’s no shortage of NFL owners that surely will be jockeying to interview him for their own vacancies.

Also burnishing Del Rio’s credentials is this fact: since Del Rio’s departure, the Jaguars are 5-26, making his record there look better and better in retrospect.