In firing offensive coordinator John DeFilippo on Tuesday, Vikings coach Mike Zimmer made a seemingly obvious decision.

DeFilippo's offense had sputtered so badly Monday against Seattle, coming very close to being shut out, that his Wikipedia page was altered by frustrated fans to read that he was the "worst offensive coordinator in the history of the NFL" (which has since been deleted, but not because fan sentiment changed). Former Vikings QB Sage Rosenfels tweeted during the game (and later deleted) "The Vikings need a new OC. Now." He got his wish.

Zimmer had spent the past several weeks barely able to hide his frustration with DeFilippo. Kirk Cousins was regressing. Nothing was going well, and happiness was as hard to come by as a relevant touchdown drive against a quality opponent. A change was inevitable and understandable.

All that said: There was a time this season when almost everyone seemed pretty happy with the Vikings' offense. Maybe it was a little uneven. Maybe Cousins was taking more hits than necessary. Turnovers were a problem. But the points … they were coming.

As the Star Tribune's Ben Goessling noted in his main piece on the firing, the Vikings were No. 8 in the NFL in yards gained and No. 10 in points through the first seven games, checking in with a 4-2-1 record after a 37-17 win at the Jets. Since then, they've been near the bottom of the NFL in both points and yards.

The Vikings lost the next week against the Saints, with two costly turnovers paving the way. Cousins put up good numbers in that game, passing for 359 yards and two TDs. At the midpoint of the season, he had 2,521 passing yards (on pace for more than 5,000), with 16 touchdown passes and just four interceptions.

From there, the reins got very tight. DeFilippo continued to be urged by Zimmer to run the ball more, even after the pass-heavy offense produced (and even after, quite honestly, DeFilippo's offense bailed out Zimmer's struggling defense in key spots in the first half of the year).

The Vikings had 22 passes and 23 runs in a 24-9 win over the Lions the next week, and Zimmer probably imagined things were back to his preferred 2017 ways.

What appears to have happened, though, is this: Cousins, wary of turning the ball over and spooked by all the hits he was taking, starting playing things safe and short. He averaged 7.4 yards per pass attempt in the first half of the season; in the five games since, Cousins has averaged just 6.4 yards per attempt. If you use adjusted yards per attempt, it's even worse: From 7.8 down to 6.1.

The competition got better during that stretch, but not enough to explain that level of regression. Plenty of that is on Cousins and his decisions. But a QB needs to be able to play free and cut it loose — trusting his instincts to find that balance between risk and reward.

And DeFilippo, in trying to please his boss with more runs, grew completely discombobulated with his play calling. There was very little feel for the game displayed against Seattle. Every key decision he made seemed to be the wrong one — like a gambler on the worst losing streak ever. Did Zimmer take away DeFilippo's strength and turn him into a constant second-guesser?

All of this leads to a quote from Zimmer on Tuesday in which he said of his involvement with the offense going forward: "Yes, I will be a little bit more involved. We've talked about that some."

Hitting rewind and going back to the 2017 model might be enough to get into the playoffs this season in the mediocre NFC middle, but that was never the goal. The goal in hiring DeFilippo and signing Cousins seemed like it was to build on last season by constructing a more dynamic offense to go with a top-notch defense — a pairing that would put the Vikings on a Super Bowl path.

The Vikings have veered way off course. Something major needed to change on offense, but the evidence says the answer isn't more of Zimmer's imprint on that side of the ball.