Isaiah J. Downing-USA TODAY Sports

When Mike Zimmer lost offensive coordinator Kevin Stefanski to a head coaching job ahead of the 2020 NFL season, the Minnesota Vikings promoted assistant Gary Kubiak to be their fourth coordinator in as many years. Now, the team will have to find yet another in 2021. According to ProFootballTalk's Mike Florio, the 59-year-old Kubiak plans to retire from coaching this offseason.

Originally hired as an assistant head coach and offensive advisor in 2019, Kubiak helped lead one of the league's most explosive units in 2020, his first season as a coordinator since 2014 with the Baltimore Ravens. Though Minnesota missed the playoffs thanks to a 7-9 finish, the Vikings boasted the fourth-ranked offense in the NFL, while scoring more points than all but 10 teams.

Under Kubiak's direction, quarterback Kirk Cousins rebounded from a slow start to throw a career-high 35 touchdowns, running back Dalvin Cook drew MVP consideration with a career-high 1,557 rushing yards, and rookie Justin Jefferson broke franchise records as the team's top receiver. The team also scored at least 27 points in eight of its final 10 games.

This isn't the first time Kubiak has retired from coaching. The former Denver Broncos head coach, who guided his team to a Super Bowl championship in 2015, stepped down from that position the following year due to health reasons. He spent the 2017 and 2018 seasons serving Denver in an administrative role before joining the Vikings.

The Vikings have looked at both internal and external candidates to fill their recent coordinator vacancies under Zimmer, promoting Stefanski from within but adding both Pat Shurmur (2016-2017) and John DeFilippo (2018) from the Philadelphia Eagles. One potential promotion for 2021 could be Kubiak's son, Klint, who has spent the last two seasons as the team's QBs coach.