There is plenty of excitement surrounding the Vikings as the 2021 season approaches.

Vikings Head Coach Mike Zimmer's squad features a revamped defense, and nearly every key piece from last season's explosive offense has returned.

And with U.S. Bank Vikings Training Camp on the horizon, what are they key storylines surrounding the team before the dog days of August arrive?

As the countdown to the first open session ticks, we'll provide a position-by-position breakdown of the most important questions surrounding each group, beginning here with the quarterbacks.

How do Kirk Cousins and Klint Kubiak work together?

Another year, another new offensive play caller for Kirk Cousins.

The Vikings quarterback enters his fourth season in Minnesota with his fourth different offensive coordinator, although there is plenty of familiarity in this relationship.

Klint Kubiak is a first-time OC, but he has experience with Cousins in the past, having spent the previous two seasons as his position coach. Kubiak takes over the role his father, Gary, held for one season.

"What's interesting to kind of work through is the offense is very similar, essentially the same, so it's not so much the plays. It's more just the personality or the communication," Cousins said in June. "The person behind the plays – the human being if you will. While that changes, there are dynamics that you want to learn and observe.

"It also is a positive that Klint has been my quarterback coach for two years. I've spent so much time with him in the quarterbacks room, and I'd like to think he really knows how I'm wired and what I like," Cousins added. "He's heard so much feedback the past couple years, and I think that certainly helps. It's been unique to look back six years (including his final two with Washington) and have six different play callers. I never would've thought that would've happened, but I've been fortunate to have been in pretty similar systems for the most part over those six years. I think that's a blessing because I think some quarterbacks have had to change systems entirely, and that's another conversation."

As Cousins noted, Klint Kubiak has implemented a similar scheme to the one the Vikings have implemented over the past two seasons. Minnesota's offense took a step forward in 2020, finishing fourth overall with 393.3 yards per game.

The potential is there for the Vikings offense to be just as good — or even better — in 2021. But a big part of that will be how Cousins and Kubiak mesh together and how the coach handles his first season in the marquee role.

"He's done a great job. The players have all the respect in the world for him, and he knows what we want to do as a football team and how we want to approach things," Zimmer said of Kubiak this spring. "I think he has a really good feel for what the players do best, which is really important."

Who wins the backup QB role?

There is zero doubt that Cousins is entrenched as the starter entering Year 4 with the Vikings and his 10th overall NFL season.

With the collection of skill players around him, Cousins could be set up for the best season of his career if all goes well.

But the Vikings will have a new backup quarterback in 2021, as Sean Mannion was not re-signed after holding that role for the past two seasons.

Minnesota now has a handful of youngsters — Jake Browning, Nate Stanley and rookie Kellen Mond — battling for that spot.

Browning has the most experience among the trio, as the 2019 undrafted free agent has spent the past two seasons on the practice squad. Stanley was a 2020 seventh-rounder who didn't get the benefit of preseason games as a rookie and spent the year on the practice squad.

Both players took the majority of the second and third-team reps this spring and have more experience than Mond, who is in the early stages in his jump to the league.

"Browning had a tremendous [offseason program], made a lot of great decisions and great throws," Kubiak said. "Stanley, he impressed as well and has come a long way. He did not get a preseason game last year, so he's chomping at the bit for that opportunity this year."

The Vikings have usually kept two quarterbacks on their Week 1 roster under Zimmer, but that could change given the addition of Mond.

What to expect from Kellen Mond in 2021?

Let's get the obvious out of the way to start: there's a strong chance Mond doesn't see the field at all as a rookie during the regular season.

Cousins and his durability have a lot to do with that, but indications from coaches this spring are that Mond has a ways to go to adapt to the speed and talent of the NFL.

"He has put in a lot of work since he got here and has come a long way in these few weeks," Kubiak said in mid-June. "They guy is a tireless worker, and he has to be because he's got to keep up with those guys ahead of him."

Added Zimmer: "Kellen has done a good job. He's hanging in there mentally with everything. The coaches are working all the time with him, continually working. He's still got a long way to go. But as far as the mental aspect of things, he's hanging in there pretty good. But he's got a lot of work to do."

Even though he was a four-year starter at Texas A&M and a third-round pick, Mond will need time to grow and develop. Every rep, whether it's in training camp or preseason games, will be a building block for his young career.

As we stated above, Mond likely won't see the field as a rookie. But with Cousins having two years left on his current deal, all eyes will be on Mond to see how he progresses in the next 12-24 months.

Fans have the opportunity to see the 2021 Vikings in person at U.S. Bank Vikings Training Camp later this month when practices at TCO Performance Center will be open to the public. Click here for ticket info about team practices, two joint sessions with the Denver Broncos and a first-of-its kind scrimmage at U.S. Bank Stadium.