MINNEAPOLIS — The lore of the Minnesota Vikings, with four losses in four Super Bowl appearances and five NFC championship game defeats since then, is marked by a long list of major letdowns.

The latest jarring blow came just before the beginning of this long-anticipated regular season, when quarterback Teddy Bridgewater’s left knee collapsed during a routine non-contact drill. The injury caused enough damage to keep him out for the rest of the year and put his 2017 season in question, too.

The massive injury to Minnesota’s popular leader was a devastating, emotional setback. Bridgewater’s absence hasn’t deterred the Vikings from thinking big, though. From coach Mike Zimmer’s inherent defiance to the bold trade made for Sam Bradford, the Vikings haven’t given up on their Super Bowl goal. Their window to win it all for the first time in franchise history is still open, albeit not as wide as a week ago.

“We’re not going to stick our heads in the sand. We’re going to figure out a way,” Zimmer said. “Everybody can count us out if they want, but I think that’d be the wrong thing to do.”

Zimmer, inspired by the lessons learned from his late father, a long-time high school coach, and mentored by former boss Bill Parcells, a member of the Pro Football Hall of Fame, has always thrived with an underdog mindset.

He didn’t get his chance to be an NFL head coach until age 57. As the Vikings stacked up victories on the way to the NFC North title last year, Zimmer frequently mentioned to the team and to the media the external skepticism surrounding their success, even if some of that was simply made up.

So when asked after Bridgewater went down how the leadership void will be filled, Zimmer zoomed right past the accomplished veterans on the roster and wholly embraced the responsibility as his own.

“I’m going to lead them,” Zimmer said. “I’m going to make sure that they’re paying attention, doing things right. Anytime you have a tragedy or whatever you want to call it, they’re going to be looking to somebody for strength and wisdom and all these other things. Part of my job is, and I’ve already started to do it, to talk to them about the things that I believe we have to do and how we need to move forward. That’s why they hired me.”

The pressure will be on Zimmer, as well as on running back Adrian Peterson and a deep, solid defense.

“It’s very unfortunate to have the injury happen,” Peterson said. “It takes a team to win a championship, so we’re still chasing the same thing.”

Here are some key angles to know about the season for the Vikings:

Replacement plan

The Vikings gave up a 2017 first-round draft pick, plus another selection in 2018 that could reach as high as the second round based on conditions, to get Bradford from Philadelphia. Clearly, the plan will be to start the 2010 first overall draft pick once he’s up to speed with the offense. Shaun Hill, who backed up Bridgewater last year and has begun his 15th season in the league, is more likely to lead the huddle Sunday at Tennessee.

THE FRONT FIVE: Some reasons the Vikings were so eager to watch Bridgewater play, and so confident in his continued development, were enhancements to an offensive line that leaked a lot in his first two years. Free agents Alex Boone and Andre Smith have taken over at left guard and right tackle. Joe Berger, who excelled while filling in for John Sullivan at center last season while the six-year starter recovered from a back injury, was good enough that Sullivan recently was let go. Brandon Fusco has returned to his original spot at right guard, and right tackle Matt Kalil has entered the final season of his contract.

Ground game

After leading the league in rushing in 2015 at age 30, Peterson also ought to benefit from better blocking in front of him. The Vikings have been planning to make versatile running back Jerick McKinnon more of an integral part of the offense, too.

The front four

The backbone of the team is a defensive line that’s as stacked and deep as ever. The Vikings tied for seventh last year with 43 sacks, and there’s the potential to land higher. Defensive end Everson Griffen, who posted 22 1/2 sacks over the last two seasons, is poised for a big year.

Raising the roof

After a couple of preseason tuneups, the Vikings will formally open U.S. Bank Stadium on Sept. 18 when they host the rival Green Bay Packers. The $1.1 billion venue was built on the same site as the old Metrodome.