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, continuing here with the offensive line.

How will Brian O'Neill handle an increased leadership role?

Brian O'Neill is continuing his impressive trajectory and will also play in key role in helping a young group develop in 2021.

Riley Reiff previously held the leadership role, but the veteran is now with the Bengals. And while O'Neill may or may not become a team captain like Reiff was, the onus is now on the right tackle who is preparing for his fourth year.

"In terms of my mentality, I don't think it changes that much," O'Neill said. "You might have a few more pointers for the young guys, but at the end of the day, it's all about trying to progress myself and have the best season I possibly can and trying to help lead this group the best way I can.

"It's been a good group so far and a great vibe around the building and great vibe in the room," O'Neill added.

A 2018 second-round pick, O'Neill has developed into one of the league's better right tackles in recent seasons. And with the lineman entering the final season of his rookie deal, he could be looking at a potential contract extension soon.

It remains to be seen if that will happen. But what's known for sure is that O'Neill will be a key piece on a very important position group that will help determine Minnesota's offensive success in 2021.

Can the rookies earn starting jobs by Week 1?

As mentioned above, the Vikings injected some youth into this position group by drafting a pair of linemen in the first three rounds this spring.

Left tackle Christian Darrisaw was the No. 23 overall pick, while right guard Wyatt Davis was a third-round selection. That continued a recent trend of early draft investments into this position group.

Can those two players earn starting roles before Week 1? The Vikings eased them into things this offseason as both players lined up with the second-team offense behind Rashod Hill and Dakota Dozier, respectively.

But with Darrisaw and Davis offering more long-term potential, perhaps they can play their way into the starting lineup with strong training camps and performances in preseason games.

There might be some growing pains early on if both do so, but the potential for success is also high if both can get adjusted to the NFL quickly.

"Darrisaw is obviously very talented," Zimmer said this spring. "He's done a nice job. He's worked real hard. He's been very attentive.

"Davis is the same way," Zimmer added. "He's got some things to work on, but they're both big guys with athleticism. Repetition is going to make them better and better."

What jump will Garrett Bradbury make in Year 3?

It's hard to believe that Bradbury is already entering his third season in the league.

Minnesota's 2019 first-round selection at No. 18 overall, Bradbury stepped into the starting role right away and hasn't looked back.

And he's been solid if not unspectacular through two seasons, showing great athleticism and learning along the way while developing a strong rapport with Kirk Cousins.

Yet the 2021 season will be a crucial one for Bradbury. Can he cement himself as the Vikings long-term center and take another step forward?

Many will be watching, including Zimmer, who said this offseason that keeping Cousins safe from interior pressure is a big point of emphasis for the offense line in 2021.

"I think it's important that we protect Kirk from inside-out. I think that's a big factor for him," Zimmer said. "If he has a clean pocket, he is obviously extremely accurate and does a great job in those areas."

Bradbury, listed at 6-foot-3 and 305 pounds, won't be confused with the biggest center in the league, but he's likely one of the most agile. He's shown supreme athleticism on screens and in the wide-zone run scheme in 32 career starts.

Can he improve his game even more and help solidify a position group that is always in the spotlight in Minnesota?

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.