DENVER -- Broncos coach Gary Kubiak informed his players after their victory over Oakland on Sunday that he's stepping away from the game and the team he loves. He said the grind of coaching was taking too big of a toll on his health.
The Broncos beat the Raiders 24-6 Sunday, a bittersweet capstone to a disappointing season that began with expectations of repeating as Super Bowl champs and ended without a trip to the playoffs.
Kubiak, 55, leaves with two years left on his contract and a 24-11 record in Denver, including a 24-10 win over Carolina in Super Bowl 50. Including his eight seasons with Houston, his career record is 87-77.
Broncos superstar Von Miller said he could see the season wearing on Kubiak.
"His health is the most important thing," Miller said.
After an Oct. 9 loss, Kubiak was taken to the hospital and diagnosed with a complex migraine , then forced to sit out Denver's next game. It was his second major health scare. In 2013, while with the Texans, he collapsed on the field and was diagnosed with a mini-stroke.
He was fired at the end of that season and had a terrific comeback in 2014 as offensive coordinator in Baltimore, where he had planned to stay until Broncos GM John Elway called him following John Fox's ouster.
Calling the opportunity a "game changer," Kubiak stepped back into the pressure cooker of head coaching on Jan. 19, 2015, when he was hired as Denver's 15th head coach.
He had spent 13 seasons there backing up Elway at quarterback and drawing up plays as his offensive coordinator.
He said at the time that his health scare in 2013 taught him to rely more on those around him. He also said he wasn't worried about the pressure of the Denver job, noting he thrived amid high expectations as a player from 1983-91, then serving on Mike Shanahan's staff from 1995-2005 and coaching the Texans from 2006-13.
Last season, Kubiak deftly managed injuries at quarterback, edge rusher and left tackle to lead the Broncos to their third Lombardi Trophy even though both Peyton Manning and Brock Osweiler struggled to run the offense.
Kubiak's offensive philosophies are rooted in Bill Walsh's West Coast system featuring the zone-blocking schemes that the Broncos fine-tuned in the 1990s and 2000s.
But in both of his seasons in Denver, the Broncos have stumbled offensively, unable to run the ball or get much production from the tight ends.
With four new starters along the offensive line this season, the Broncos again sputtered behind poor blocking and a battered backfield, where C.J. Anderson, Andy Janovich and Kapri Bibbs ended up on injured reserve.
Under incessant pressure, neither Trevor Siemian nor Paxton Lynch settled in at quarterback.
Siemian suffered injuries to both shoulders and his left foot, forcing him to miss 2½ games. In those games, Lynch, the 26th overall pick out of Memphis, showed he was far from adapting to the pro game.
With Kubiak stepping down, possible replacements include Miami defensive coordinator Vance Joseph and Atlanta offensive coordinator Kyle Shanahan.
Big changes were expected on offense even if Kubiak returned, because of a season-long, head-scratching inability to start faster. The Broncos scored an NFL-worst 40 first-quarter points and had just two sustained touchdown drives in the first quarter all season, including one Sunday.
Slow starts meant playing from behind too much, and that, in turn, defanged their strengths: Miller sacking quarterbacks and wrecking game plays and Pro Bowl cornerbacks Aqib Talib and Chris Harris Jr. shutting down receivers.
The Broncos also missed run-stuffers Malik Jackson (free agent departure) and Vance Walker (season-ending knee injury in camp) and their run defense slipped from top-3 to 29th.
Sunday's game against the Raiders was the first for Denver since 2010 without any playoff implications.
"I'm glad we sent him off with a win, though," Siemian said.