In this Dec. 24, 2017, file photo, Chicago Bears defensive coordinator Vic Fangio watches before an NFL football game against the Cleveland Browns, in Chicago.

Nam Y. Huh/ AP Photo

Published 1:21 p.m. | Updated 6:10 p.m.

Forget RPOs. John Elway is going with AARP.

The Chicago Bears defensive coordinator Vic Fangio, 60, has accepted Elway's offer to become the Denver Broncos' next head coach, a person with knowledge of the agreement told The Associated Press on Wednesday.

The person spoke on condition of anonymity because the Broncos didn't announce the hiring, something the team won't do until Fangio signs his contract. He's expected to be introduced as the club's 17th head coach on Thursday.

Fangio replaces Vance Joseph , who was fired on New Year's Eve after posting the franchise's first back-to-back losing seasons since the early 1970s.

Fangio and Elway, who turns 59 this summer, will make up one of the oldest coach-GM duos in the NFL in 2019.

Although Fangio, who turns 61 in August, has no NFL head coaching experience, he has been an assistant for 32 years in the NFL and 34 seasons overall, beginning with the Philadelphia Stars of the old USFL in 1984.

Just like former Denver defensive coordinator Wade Phillips, Fangio relates to players less than half his age and commands a deep respect in the locker room.

"You're talking about one of the best coaches in football," Bears star edge rusher Khalil Mack said recently, dubbing Fangio "the evil genius himself."

Elway said when he began his search for his fourth head coach in six seasons that he values experience but also recognizes the need to modernize the Broncos' offensive and defensive schemes to keep up with the run-pass option craze that has swept through the NFL and rendered traditional systems antiquated.

Elway didn't believe that innovation necessitated a young, up-and-coming head coach, however. So, instead of going with a fresh-faced offensive-minded novice in the mold of the Rams' Sean McVay, he zeroed in on the grizzled gridiron lifer who's more like his first head coaching hire, John Fox, or even the Chiefs' Andy Reid.

Joseph was also a first-time head coach with deep defensive roots, but he lacked the lengthy resume Fangio brings. Whereas Joseph had just one year of experience as a coordinator, Fangio brings 19 years of coordinating experience for the Panthers, Colts, Texans, 49ers and Bears.

He's built dominant defenses in different eras, successfully adapting to changes in personnel, philosophies and style.

The 2018 season was his best as Fangio guided a Bears defense that ranked No. 1 in the NFL, allowed a league-low 17.7 points per game and led the Bears into the playoffs for the first time in eight years.

In addition to Mack, who joined the Bears in a trade from Oakland, three other Bears defenders were selected to the Pro Bowl under Fangio's watch in 2018: safety Eddie Jackson, lineman Akiem Hicks and cornerback Kyle Fuller.

Fangio was available to take over in Denver sooner than expected because of the Bears' stunning 16-15 loss to the Philadelphia Eagles in the wild-card round last weekend. Eagles defensive lineman Treyvon Hester tipped Cody Parkey's last-second field-goal attempt that clanked off the left upright and the crossbar.

Several Bears players were hoping the Broncos would choose one of Elway's other candidates — Steelers O-line coach Mike Munchak, ex-Colts coach Chuck Pagano, Patriots linebackers coach Brian Flores or Rams QBs coach Zac Taylor.

When word got out that Elway had chosen Fangio, Bears cornerback Prince Amukamar a tweeted the hashtag "curse words" and Chicago wide receiver Allen Robinson II tweeted the broken heart emoji.

Fangio inherits a Broncos team that's coming off back-to-back losing seasons for the first time since 1971-72, a hard fall for a franchise that was hoisting the Lombardi Trophy just three years ago thanks to Von Miller's MVP performance in Super Bowl 50.

Peyton Manning retired a month later and the Broncos have cycled through four starting quarterbacks since, including free agent Case Keenum, who was underwhelming during Denver's 6-10 season that included two four-game skids.

Elway said last week that personnel assistant and former Broncos head coach Gary Kubiak will move back into an offensive assistant coaching role in Denver in 2019. Kubiak stepped aside over health concerns a year after guiding Denver to its third Super Bowl victory.

Last month, Miller suggested that a defense can still lead a team to a title like Denver's did three years ago even in this age of potent offenses incorporating college concepts and running up scores.

"The Bears have been doing it right. They get takeaways, they play tight coverage and they got a great run defense," Miller said. "I feel like the Bears definitely got a defense that can go all the way."

Instead, the Bears' season ended earlier than expected, and now the man Mack dubbed an "evil genius" will join Miller in Denver.