As Vikings coach Mike Zimmer explained his decision to fire offensive coordinator John DeFilippo the morning after the team's 21-7 loss at Seattle, he fixated on a stretch that's seen the team go from the top of the NFC North to a fight for the final playoff spot.

"We had to shake things up and try to get better as a football team together," Zimmer said Tuesday. "I didn't feel like we were going in that direction based on the past four or five weeks. It wasn't about one game. It's about the direction we were going throughout the latter part of the season."

DeFilippo took the fall for a clunky offense that's also sputtered because of a beleaguered offensive line and quarterback Kirk Cousins' ill-timed turnovers. But his departure also comes at the end of a two-month span that revealed the philosophical gap between the 40-year-old coordinator and his boss.

Zimmer first publicly called for more offensive balance the day after the Nov. 18 loss to the Bears; sources have said his push to run more started internally around midseason. He reiterated concerns about the commitment to the run after a Dec. 2 loss to the Patriots.

The Vikings were eighth in the league in yards and 10th in points through seven games, after they put up a season-high 37 points on Oct. 21, improving to 4-2-1 with a victory over the Jets on a windy day at MetLife Stadium. In their six games since, they have averaged 324 yards and 17.5 points per game, ranking near the bottom of the league in both categories.

In three of those six games, the Vikings ran on a majority of first and second downs in the first half, though their commitment to the run has sometimes flagged, most notably at New England, when they ran only six times in the second half after averaging 9.6 yards per carry in the first.

The Vikings ran 21 times in their first 48 plays Monday, though they threw on four of five third-and-short situations while the game was still within reach, converting only one on a Cousins QB sneak. They came within minutes of their first shutout since a 34-0 loss to the Packers in 2007. By Tuesday morning, Zimmer decided he needed to make a change.

"I just didn't think we were making enough advancement in this part of the season to continue to go forward the way we want to go forward," he said Tuesday. "I'm not going to get into specifics about some of the things. I just felt it was in the best interest of the team to make this move now."

Stefanski gets a look

Former QB coach Kevin Stefanski is the Vikings' fourth offensive coordinator — and their second interim coordinator — in three seasons. Two years ago, Norv Turner's resignation opened the door for Pat Shurmur to go from the interim job to the permanent spot, which in turn got him the job as New York Giants coach. Now, the Vikings will turn to Stefanski, whom they blocked from joining Shurmur after hiring DeFilippo last offseason.

When the Giants hired Shurmur, following a season where he had directed the 10th-highest scoring offense in the NFL, Vikings General Manager Rick Spielman spoke of the team's desire for continuity on offense. But instead of hiring Stefanski — the longest-tenured assistant in the organization and someone who was thought to be the early frontrunner for the job — Zimmer and Spielman flew to Philadelphia on Feb. 8 to hire DeFilippo hours after the Eagles' Super Bowl parade.

In doing so, they landed a descendant of Andy Reid's coaching philosophy who learned under Doug Pederson in Philadelphia. A young offensive mind who had already received head coaching interest following his work with Carson Wentz as Eagles quarterbacks coach, DeFilippo played a pivotal role in the Vikings' decision to go after Cousins in free agency, and he met with Zimmer to revisit how the Eagles had dissected the Vikings defense in the NFC Championship Game. DeFilippo often threw to set up the run; Stefanski's tutelage under Shurmur might prompt a return to more of what the Vikings did last season.

Uncertainty ahead

The Vikings' offensive future, though, is far from settled.

Zimmer responded to criticism over the decision to block Stefanski at the combine in March, saying he had shown loyalty to his offensive coaches by not firing them after bad seasons, and he expected them to return the favor by not seeking promotions with other teams after good ones. Now, Stefanski will get a three-game audition in the job he wanted 10 months ago, with his contract believed to be expiring at the end of the year. Asked if Stefanski would be a long-term candidate, Zimmer said: "We'll see how things develop here. Obviously, it would be in his best interest to do well."

And multiple sources have said Zimmer's and Spielman's contracts are up after the 2019 season, meaning the Vikings could face decisions about new deals for both men this offseason If the situation is not resolved before the Vikings find their next permanent offensive coordinator, candidates — Stefanski or otherwise — will have to weigh the job's inherent risks against the upside of an offense replete with weapons like Adam Thielen, Stefon Diggs and Dalvin Cook.

One way or the other, the Vikings appear headed for another period of uncertainty on offense.

"I talked to some of the players afterward and they all feel bad for John because no one believes it was one person's fault," Zimmer said. "But I think they probably understand the sense of urgency going forward."

Ben Goessling covers the Vikings for the Star Tribune. ben.goessling@startribune.com