Mike Zimmer’s team lost a second straight game by a double-digit margin, with a depleted offense sputtering badly.

The next day he needed eye surgery.

The following morning, his offensive coordinator came into his office at Minnesota Vikings headquarters to inform him of his resignation.

All this after overcoming the absences of several injured starters to take the NFL’s only 5-0 record this season into the bye week.

“I feel the roller coaster ride,” Zimmer said, flashing a smile that’s been rarely spotted on his grizzled face lately.

That’s the life of a head coach. Even for assistants. Zimmer took some time after a recent practice to recall his second year in the league, 1995, when he was defensive backs coach for a Dallas team that won the Super Bowl trophy.

Beaten by then-rival San Francisco in the previous NFC championship game and again that regular season, the Cowboys slumped a bit in December and needed a win and a one-point loss by the 49ers on the final weekend of play to gain home-field advantage throughout the playoffs. Green Bay knocked off San Francisco in the division round, and the Cowboys took down the Packers for the NFC title before beating the Pittsburgh Steelers for the championship.

“At the end of the year, regardless of what happens, I went in the locker room at the end of the game and said, ‘My God, that was a long season,’” Zimmer said. “So I get it. That’s just how this thing works. We’re not the only team to have ups and downs.

“Hey, it’s the NFL.”

The Vikings (5-2) host Detroit on Sunday, eager to return to raucous U.S. Bank Stadium where they’re unbeaten in three games. The Lions (4-4) know all about those ups and downs, of course, looking back to last year’s 1-7 start that rendered a 6-2 finish meaningless. This season, every game has been close, winning by four points or fewer each time for a cumulative margin of victory of 11 points. Four defeats, all by a touchdown or less, have come by a total of 18 points.

“Just take a look at it, and you’ve always got a chance at this point in time, right?” Lions coach Jim Caldwell said. “Goals are still in front of you.”

Here are some key angles to know about the game:

Midseason switch

After losing to Minnesota 28-19 in Detroit last year, watching Matthew Stafford take seven sacks, Caldwell fired offensive coordinator Joe Lombardi and both offensive line coaches. Quarterbacks coach Jim Bob Cooter took over the play calling, and Stafford and the Lions were far more effective after that. They’ve kept up that success on offense this season.

“What we had to do was work extremely hard. You had to little by little kind of piece something new together that we wanted to do, and go from there,” Stafford said, recalling the challenge of the change.

Though the circumstances are different, the Vikings would love a similar boost for their offense after Norv Turner left and was replaced by Pat Shurmur.

“It’s not on coaches. We’re the ones out there. We’re the ones that need to play better,” tight end Kyle Rudolph said. “Moving forward, we’ve just got to get everybody to do their job. We have the talent and ability to make that happen.”

Protecting the passer

There’s no question about Shurmur’s top priority in taking over the offense. Bradford needs better protection than he received the last two games if the Vikings are going to get back on track. Bradford was not only sacked 11 times but hit hard on several other throws, sending him out of sync after playing so crisply and effectively before the bye.

“I don’t think it’s a good thing,” Bradford said. “I think we’ve got to figure out a way to bring that number down.”

Getting there

Lions defensive end Ezekiel Ansah, who missed three earlier games because of a sprained ankle, is still without a sack. Ansah, who finished 2015 with 14½ sacks, has five sacks in six career games against the Vikings.

“Maybe the first week or so he got maybe a little bit rusty, but I think without question he’s still who he is,” Caldwell said.

Stopping the run

The issues with the offense had already been exposed before the loss at Chicago on Monday night, so the ease with which Bears rookie Jordan Howard ran through Minnesota’s front seven and secondary was more alarming. Howard rushed 26 times for 153 yards and caught four passes for 49 yards.

“That’s inexcusable for us on defense,” linebacker Chad Greenway said. “That’s what we pride ourselves on and have for a long time.”

Stafford’s surge

Over the last 16 games, mirroring Cooter’s move into the offensive coordinator role, the Lions are in the top three in the NFL in passer rating, touchdown-to-interception ratio, completion percentage, passing touchdowns and offensive points scored among other categories.