While Minnesota and Chicago are plenty familiar with each other from playing twice a year, the first matchup of the season between the NFC North teams brings more intrigue than usual.
The Bears (6-3) are a different team after making some big changes in the offseason that appear to be paying off. They're leading in the division, just ahead of the Vikings (5-3-1), which means this game is for first place.
Matt Nagy was hired to be Chicago's head coach after five seasons in Kansas City, most recently as the offensive coordinator. Receivers Allen Robinson II and Taylor Gabriel, and tight end Trey Burton were signed in free agency. Receiver Anthony Miller was a second-round draft pick to continue the offensive alterations.
"Their team speed is much better now," Vikings head coach Mike Zimmer said. "Those guys have all added a lot of things to them. Then you throw in there (Tarik) Cohen and Anthony Miller, who has done a nice job. They're opening things up a lot more. This isn't two yards and a cloud of dust deal."
Nagy altered the Bears' offense and helped second-year quarterback Mitchell Trubisky take a big step. Trubisky is completing 65.5 percent of his passes for 2,304 yards, 19 touchdowns and seven interceptions. He has also run for 320 yards and three touchdowns.
"He gets the ball out with accuracy," Zimmer said. "There's other times he looks like Fran Tarkenton scrambling. Some of the runs he's made are unbelievable. They're obviously using him in a bunch of different ways.
"I think the command of the offense is probably his biggest thing is being able to go through progressions more, now."
Nagy has also transformed the defense, and Mack plays a big part of the new look.
"I think he's added a lot of swagger to the football team," Zimmer said of Mack. "I think they have swagger anyway, but I think he's added some to it knowing that they've got a guy of his caliber that's in there. He really adds a lot of physicality to their defense. I think that's part of it."
Chicago drafted speedy linebacker Roquan Smith in the first round, and he has 63 tackles and three sacks.
The Bears rank fourth in the league in total defense, one spot ahead of the Vikings. They have 30 sacks, which is fifth in the league, and have the second-most takeaways in the NFL this season with 16 interceptions and eight fumble recoveries.
"Obviously, they've improved, they're healthy, I don't think they've had a lot of injuries defensively, and adding a guy like him is going to be a big factor in getting them better," Zimmer said. "I think it allows them to play the style of defense that they would like to play."
The lights will be brighter on Sunday night, but to Smith it isn't that big a deal.
"People think it's bigger because they flexed it to the night game," Smith said. "It doesn't make a difference to me."
When Minnesota's defense is on the field, it will be out to stop the Chicago offense. The Vikings are fifth in the NFL in total defense, giving up 322.2 yards per game.
"Defensively, we've obviously improved in the last five weeks a ton from where we were," Zimmer said. "We're playing much better on the back end, not giving up near as many big plays. The run game, we've always been pretty decent against the run. I just think overall in some of the key areas we've improved quite a bit."
The Bears' trigger man is Trubisky, who has come a long way since his debut last season when he threw a game-deciding interception to the Vikings' Harrison Smith in a 20-17 loss.
In a sense, Trubisky is back where it all started, facing the Vikings at home in a big night game.
"I think I've grown a lot since that play," Trubisky said of the interception. "I'm not the same player, not even close. I've got better since that instance and I'm excited for the opportunity this weekend."
Last week against the Detroit Lions, Trubisky threw for a career-best 355 yards with three touchdowns and was named the NFC offensive player of the week.
"I think just good feet, good eyes and I just played with conviction," Trubisky said. "I made a decision that I was just in a good mind-state, just go out there and play confident."