Add another check mark to the list of firsts at U.S. Bank Stadium. There was the first event (a sold-out soccer game), the first concert and most recently the first actual football game, which was Sunday when the Vikings defeated the Chargers in the “all-important” third preseason game.

The next first — the Sept. 18 regular-season home opener against Green Bay — will top them all and add to the gawking. Soon, though, U.S. Bank Stadium will settle into what it is: a place fans will appreciate, but one whose aesthetics typically will come second to the product the Vikings put on the field.

This isn’t baseball, where the pace and fan mentality put an added emphasis on the facility — to the point that pilgrimages are built around seeing all the MLB stadiums around the country. People still talk about how nice Target Field is even though the Twins have struggled during the majority of its existence. If the Vikings stink? Fewer people will be talking about the building.

As such, even as the building played a starring role Sunday, here are a few observations from the day that are mostly about football:

Three old strengths

• Teddy Bridgewater is an underrated runner, and the moves he put on display during a 22-yard scramble only added to that sentiment.

• Jerick McKinnon looked sharp running the ball. Just as impressive as his 35-yard scamper was his tough 2-yarder on third-and-2 deep in Vikings territory to extend a drive.

• Harrison Smith had an interception. Anthony Barr swarmed to the ball. These guys are the stars of the back seven, and they looked the part Sunday.

Three old questions

• Vikings QBs were sacked five times in the first three quarters.

• Run defense was an issue last season. The Chargers’ Melvin Gordon had a very easy-looking 39-yard touchdown run.

• The Vikings were 27th in red zone TD percentage last season, and their first two scoring drives Sunday ended in short field goals. Those threes need to become sevens.

Two intriguing developments

• It’s hard to remember many three-throw sequences like the one Bridgewater had near the end of the first half: a strike over the middle to Charles Johnson, a deep out to Stefon Diggs and a bullet over the middle into a tight window to Kyle Rudolph for a TD. If that’s what the coaches mean by “cut it loose,” the Vikings are on to something.

• The Vikings’ defensive depth is becoming a strength. When you don’t lose a lot of players off a very good defense while several young players keep developing, you get a very good second unit.

The final word

I asked Vikings fans on Twitter what they liked/didn’t like about the new stadium experience. @bigcat4life said he had just one complaint: Turn the volume down on the music “a notch or two.”

Meanwhile, @Rogerskolney had an appreciation for the space. “I’ll tell you that anyone complaining about the concourse width is nuts. Night and day from the dome.”

As someone who gets claustrophobic just thinking about the old space, there’s no argument here.