Vikings offensive coordinator Gary Kubiak made his widely-expected retirement official on Thursday afternoon, meaning the team's offensive play-caller in 2021 will be its sixth in as many years.

Kubiak, who joined the Vikings as an assistant head coach in 2019 to work on Kevin Stefanski's offensive staff, took over as offensive coordinator after the Browns hired Stefanski before last season. Kubiak directed an offense that finished fourth in the NFL in scoring and 11th in yards.

After one year in the coordinator role, though, Kubiak, 59, decided to step away. It is his second retirement; he left the NFL as the Broncos' head coach after the 2016 season.

"It's been the honor of my lifetime to work for 36 seasons as an NFL player and coach," Kubiak said in a statement. "I've been on a football field for most of my life, and now I look forward to stepping away from the game and enjoying more time with my family and friends. If offer my sincere thanks to the owners and fans of the Minnesota Vikings, Denver Broncos, Baltimore Ravens, Houston Texans and San Francisco 49ers for giving me opportunities to be a part of this great game and for treating me and my family so well over the years."

The Vikings are expected to go through a formal interview process for Kubiak's replacement and are required by NFL rules to interview at least one external candidate of color for the job. But sources said this week Kubiak's son Klint, the Vikings' quarterbacks coach the past two years, is thought to be a leading contender for the job.

Klint Kubiak's relationship with Stefanski was the catalyst for both Kubiaks, offensive line coach Rick Dennison and tight ends coach Brian Pariani to join the Vikings before the 2019 season. The younger Kubiak's work with quarterback Kirk Cousins could give the team the continuity it will likely seek in a new coordinator.

"I love the scheme that we're running offensively," coach Mike Zimmer said in his season-ending news conference on Jan. 5. "I love the wide zone offense, I love the play-action passes. All those things. A coach told me one time that your offense should be what your quarterback is best at. And that's what I feel Kirk is best at. Those kind of things are what makes him really good. So to me, that is really important."

If Klint Kubiak becomes the Vikings' next coordinator, the team has discussed the possibility of moving wide receivers coach Andrew Janocko to the QB coach. A former college quarterback, Janocko has built a solid reputation in his six years on the Vikings' staff and won plaudits in the organization for his work with rookie Justin Jefferson this year. The Detroit Free Press reported on Thursday afternoon that Lions wide receivers coach Robert Prince could be a candidate to serve in the same role on the Vikings.

Kubiak's retirement now leaves the Vikings with three openings on their staff; the team did not renew special teams coordinator Marwan Maalouf's contract and will look for a new strength and conditioning coach after parting ways with Mark Uyeyama. The Vikings' 2021 coaching staff might not be finalized until after the Super Bowl.

After winning a Super Bowl ring as an assistant coach in San Francisco and two more as the Broncos' offensive coordinator, Kubiak spent eight seasons as the Texans' head coach, leading the team to the playoffs in 2011 and 2012 before he was fired with three games to go in 2013. He returned as the Broncos' head coach in 2015, leading the team to a Super Bowl victory before retiring after the 2016 season.

He collapsed on the sideline that year as the result of a transient ischemic attack, and health concerns caused him to walk away. At the end of the 2020 season, Zimmer said Kubiak needed some time to go through his options and assess his health before deciding whether to come back.

In the end, Kubiak decided it was time for him to step away.

"Gary did a tremendous job with us at the Vikings over the past two seasons," Zimmer said in a statement. "I have a great deal of respect for him as a coach and a person, and I'm glad I was able to coach with him. He has had one heck of a NFL career as a player, assistant coach and head coach, and I am really happy for Gary and his wife Rhonda as they head off to their ranch."