MINNEAPOLIS >> A discouraged Brock Purdy stepped off the media dais when he received a pat on the back from a sharply dressed man in a black vest and white collared shirt.

Purdy did a double take. “Whoa, whoa, I didn’t know that was you,” Purdy said to Fred Warner, the 49ers’ All-Pro, All-World, All-Over-The-Place linebacker.

They clasped their right hands together and patted each other on the back, then Warner took his turn at the microphone to dissect the 49ers’ 23-17 loss to the Vikings that would have been lopsided if not for him. He made an interception at the 49ers’ 10-yard line, forced a comeback-inspiring fumble at the 2, forced another fumble on a sideline sack of Sam Darnold, made a third-down pass breakup, had a tackle for loss and (probably) fished 15,000 walleye out of Lake Minnetonka.

Warner’s job wasn’t over after the 49ers’ initial loss of a Super Bowl hangover season. He addressed the team afterward with a clear message: “We have so much talent in that room and we’re always going to play hard. But it’s about playing smarter.”

Each of his teammates rightfully fawned over Warner’s game, with the added disclaimer that they all have to follow his lead and play like him. They didn’t Sunday. They lost an eighth straight visit to Minnesota.

Here are some things that caught my eye – and made me go “whoa, whoa” – in covering the 49ers’ first defeat since that Las Vegas boondoggle back in February:1. Missing McCaffrey

The 49ers offense isn’t anywhere near as potent as when Christian McCaffrey is in there, especially in the red zone when there is a glaring need for a touchdown. This is the 49ers’ life as McCaffrey idles on injured reserve with Achilles tendinitis for at least three more games. Coach Kyle Shanahan said surgery has not been discussed, but IR wasn’t under discussion three days before it became the move.

“There are things we can’t do without Christian,” said tight end George Kittle.

“He has an incredible impact on this team. Just him being around, he boosts everyone’s confidence,” Kittle said. “But I mean, we won last week. I think we had opportunities to find a way to win (Sunday) and we just didn’t.”

2. Respecting Mason

Mourning McCaffrey’s absence is not a disrespectful dig at his replacement, Jordan Mason. The undrafted third-year rusher continues to impress with his ability to identify holes, power through defenders or even stop on a dime and redirect himself upfield.

Mason hit the 100-yard rushing mark (on the nose, on 20 carries) after a 147-yard starting debut in Monday night’s win over the New York Jets.

With such production, the 49ers ignored him on third-and-1 from the 4-yard line and Purdy instead attempted a backward pass that was nearly intercepted before Deebo Samuel secured it for a 9-yard loss to set up Jake Moody’s late field goal. The 49ers also threw on fourth-and-goal from the 2 in the second quarter, and the pass got tipped and fell incomplete.

3. Slow starts

The 49ers failed to pick up a first down on their opening possession for the second time in as many games. And like Monday’s debut against the Jets, Purdy failed to complete a third-and-short pass to Samuel.

Whereas Purdy delivered scoring drives on all his eight ensuing series in the season opener, this game went: blocked punt, downs, downs, touchdown, punt, interception, fumble, touchdown, field goal.

“It’s back-to-back weeks we’ve started out like this, with two not-great drives to start off,” Kittle said. “So as an offense, we have to start better than that and not just have to rely on our defense.”

4. Anyone see Aiyuk?

The 49ers offense trudged along in the first half without much action to Brandon Aiyuk, who had a 2-yard catch and only one other target. Whose fault is it that the $30 million-per-year receiver couldn’t show his worth the way the Vikings got 133 first-half yards out of Justin “$35 million” Jefferson?

Aiyuk is understandably rusty after skipping practice through training camp and the preseason, and he couldn’t shake safety Harrison Smith on one third-down route as Purdy spied him. Don’t lose hope, however.

Said Purdy: “There are probably a couple of routes in certain looks we could have both been better, but that’s early-season stuff. We’ll continue to get better together with our connection. For four quarters, B.A. grinded and competed.” Aiyuk had three catches after halftime: 22, 7, 12 yards.

5. Third-down trauma

Like any loss, third-down deficiencies and turnovers are often to blame. Well, the 49ers came away even on turnovers. That meant third downs served as a great scapegoat.

Offensively, they converted 2-of-10. Defensively, the Vikings succeeded on 7-of-12. “It’s on me to move the ball, be efficient on first and second down and get us into third-and-manageable and then convert on third down,” said Purdy.

Shanahan noted his defense got the Vikings in some critical third-down spots, only to have Sam Darnold convert a trio of third-down passes that set up the Vikings’ insurance field goal. “It’s a big part of the game, third down,” Nick Bosa said. “That’s why we have a whole day based on third down. It’s how this league is, and we failed.”

6. Special teams woes

Having a punt blocked in the first quarter is a great way to ruin a day. C.J. Ham came unblocked through the right side (past Demetrius Flannigan-Fowles) to block the punt by Mitch Wishnowsky, who strangely stood still rather than pounce on the live ball.

Sadly, such special teams mishaps don’t seem too unusual in this 49ers era. Nor was it shocking to see rookie punt returner Jacob Cowing botch a fair-catch attempt at the 10-yard line; lucky for him, Isaac Yiadom recovered for the 49ers.

Cowing was accountable afterward at his locker. He explained that he got off balance when he saw how close a defender was coming. “I’m just trying to keep my head positive, have a short memory, moving on to the next week and get better,” said Cowing.

All that said, one muffed punt could be all the 49ers need to summon Trent Taylor off the practice squad to return punts.

7. Minnesota mystique

U.S. Bank Stadium opened its ninth season with the cacophony expected from arguably the NFL’s noisiest and most energetic atmosphere.

“It hurts my soul, honestly. We knew type game going to be and what it would take,” Warner said of the 49ers’ eight-game losing streak in Minneapolis and third straight loss since this stadium replaced the Metrodome.

It wasn’t surprising to see the 49ers commit false-start penalties, one apiece by tackles Trent Williams and Colton McKivitz. Rookie right guard Dominick Puni otherwise signaled center Jake Brendel to snap the ball on time to Purdy. “We definitely knew what we were getting into. We played here before,” said Brendel, alluding to last October’s loss. “We understand their fans are really loud, and an indoor stadium is always going to echo more.”

8. Overcoming defeat

The locker room was as solemn as expected after any loss. The gravity of a regular-season defeat cannot compare to the 49ers’ last loss seven months ago in Super Bowl LVIII.

The 49ers will not challenge the 1972 Miami Dolphins as undefeated Super Bowl champions. But their NFC title defense remains very much in play.

The 49ers’ title aspirations always start with winning their division, and a critical step in that comes next, when they play Sunday at Levi’s South, otherwise known as the Los Angeles Rams’ SoFi Stadium; the 49ers are 4-0 in regular-season games there.