The NFL has yet to field a team — be it good, bad or ugly — that wasn't bursting with unbridled optimism at each and every question hurled its way during a training camp news conference.

A year ago, Ed Donatell was the Vikings' new defensive coordinator. He replaced the fired Mike Zimmer, head coach and de facto defensive coordinator, whose 2021 team allowed 426 points, sixth-worst in franchise history.

Based on the Purple podium praise gushing forth from last year's training camp, the scheme Donatell and Vic Fangio had concocted through successful stints in San Francisco, Chicago and Denver was going to storm the Twin Cities and stump every QB and offensive coordinator in its path.

Right, 2022 Kirk Cousins?

"It's really muddy," the Vikings quarterback said last year. "So when you drop back, you don't quite know what you're getting. … I think it's a great scheme, and they do a great job. It just makes practice difficult."

Coach Kevin O'Connell concurred heartily at the time, saying, "That family of defense has really caused a lot of people problems, and it's because it puts a lot of stress on the quarterback."

Six months later, O'Connell fired Donatell after a 13-4 season ended with a first-round home playoff upset loss to the Giants. Donatell's defense finished 31st in the NFL in yards allowed (388.7) while giving up 427 points to replace Zim's 2021 squad as sixth-worst in franchise history.

Moral of the story: Talk is cheap. Especially in July.

Enter Brian Flores, O'Connell's defensive coordinator mulligan. He arrived as an aggressive, blitz-happy Bill Belichick protégé who went on to experience some defensive success as head coach of the Miami Dolphins.

Flores is the anti-Ed in mentality, age, play-calling aggressiveness and, well, you name it. How he weds all that personality with a defensive personnel returning only five starters while losing Patrick Peterson, Eric Kendricks, Dalvin Tomlinson and Za'Darius Smith is the No. 1 key to whether the Vikings defend their NFC North title and advance further in the playoffs this season.

So, Brian, what are your top one or two concerns? And no rosy, Ed-like training camp sugarcoating, please.

"I'm concerned with everything," Flores said before the first training camp practice on Wednesday. "There's not a part of the defense that we're not going to coach our butts off to make sure it's right."

He didn't mention the obvious No. 1 concern as camp opened with Danielle Hunter, one of the league's top edge rushers, present but withholding his physical services until his contract is restructured or the Vikings trade him.

Hunter also skipped the team's mandatory minicamp and its voluntary OTAs, but Flores said he's not worried about Hunter's ability to catch up if the two sides do indeed reach a financial agreement.

"I think veteran players, they've seen a lot of defenses, a lot of coverages, stunts, fronts," he said. "I think terminology is the one thing that's a little different. But some of it is crossover from what he's heard in the past, so I don't think it will take him long to get up to speed.

"And," Flores added with a smile, "at the end of the day, we tell him to 'Go get the quarterback,' so there's not much to that."

Another somewhat, if not all-out, frightening question mark early in camp is the cornerback position.

"It's going to be a competitive camp," Flores said. "We've got a lot of guys who showed well in the spring, in meetings. And they've come back ready to go."

Believe it or not, the presumed top five corners — Byron Murphy Jr., Akayleb Evans, Andrew Booth Jr., Mekhi Blackmon and Joejuan Williams — enter camp with experience and durability concerns.

Murphy, 25, is essentially the grizzled veteran of the group with 48 starts and five interceptions. He missed eight games with a back injury in Arizona last year.

Evans had more stints in the NFL's concussion protocol (three) than starts (two) as a rookie last year. Booth's long list of career injuries continued with multiple ailments throughout 2022, limiting him to six games and one start as a second-round pick.

Williams, once a promising second-round pick of the Patriots, missed all of last season with a shoulder injury. And Blackmon is a rookie Day 2 pick.

Those who say, "Oh, well, the defense can't be any worse than last season" are forgetting four one-score nailbiters against the Lions, Bears, Jets and Bills. Takeaways by Donatell's defense in the final 1:19 of regulation or overtime preserved each of those wins.

Flores isn't making any promises about 2023. And that's a good thing since talk is, well, you know.

"What I know is the good defenses I've been a part of, they have a lot of fun," Flores said. "We're going to try to do that."