December failures add up and could leave Vikings coach Mike Zimmer on notice

Following the most embarrassing performance of his Vikings tenure, Mike Zimmer faces what might be the least meaningful game of his head coaching career Sunday.

Imagine this as a marketing pitch: The Vikings will try to avoid a double-digit loss season without their most important player against one of America's worst franchises, in the last game of the Lions' interim head coach's tenure with Detroit's star quarterback and receiver looking unlikely to play.

To Zimmer's credit, the Vikings haven't played many meaningless games on his watch, and one that didn't matter — last year's loss to the Bears to end the 2019 regular season — was meaningless because the Vikings already had made the playoffs.

Entering this season, Zimmer had made the playoffs in three of the past five seasons, and he can be forgiven for lamenting the absence of Danielle Hunter and Michael Pierce this season. His defense requires an outside pass rusher and an interior run stopper, and already was breaking in new cornerbacks. Some excuses are legitimate.

But Zimmer is in the midst of negative trends that extend beyond this season. He has entered his past three Decembers with contending teams carrying championship aspirations. The past three Decembers his teams are 5-9.

In 2018, the Vikings went 2-3 to finish 8-8 and out of the playoffs. In their finale, they no-showed at home, losing 24-10 to Mitch Trubisky and the Bears in the biggest game of the season.

In 2019, they no-showed in the regular season's penultimate game, losing to the Packers 23-10 at home.

Why would a team led by an experienced veteran coach repeatedly flop in what can be the decisive month of the season?

Three theories:

1. He wears down his teams: Zimmer believes in physical practices. Most teams prefer to preserve their players' legs for game day. Zimmer might be too old-school for his own good.

2. He's grumpy: There is no obvious correlation between a coach's mood and his winning percentage, and how a coach behaves in front of the news media is irrelevant. But ... Zimmer becomes increasingly gruff and monosyllabic as the year progresses. If his mood worsens around his players, that could affect team morale. NFL players risk their health on every tackle. A lack of affection for your head coach can dampen resolve.

3. Other teams figure out his defense: The last game of the Vikings' 2017 season, they allowed 38 points. The last game of the 2018 season, they allowed 24 to the Bears. The last game of the 2019 season, they allowed 27. The last game of December 2020, they allowed 52. For a team that was built defense first, those are frightening numbers.

The 2017 Vikings won 13 regular-season games yet were destroyed by quality offensive coaches — New Orleans' Sean Payton and Philadelphia's Doug Pederson, Frank Reich and John DeFilippo — in the games that mattered most.

Now Zimmer faces a game that matters not at all. The Vikings would be better off losing and moving up the draft board than winning to remain in third place in the NFC North.

The game seems to matter a lot to Zimmer. Listening to him talk this week, there is little doubt he wants to beat the Lions and enter the offseason with a modicum of optimism and the ability to view the New Orleans performance as an aberration.

Perhaps the only aspect of the Lions game that will matter is whether his defenders look interested in playing for him. If that doesn't happen, Zimmer will be on notice when the 2021 season begins.