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.

Minnesota, however, is replacing a 10-year mainstay in the lineup at tight end after bidding farewell to Kyle Rudolph this offseason to save cap space.

With U.S. Bank Vikings Training Camp set to open later this month, what are they key storylines surrounding the tight ends?

Is Irv Smith, Jr., ready to be become a household name?

Smith has put up solid numbers in his first two seasons in the league, catching 66 passes for 676 yards and seven scores. If all goes well for Smith and the Vikings, the tight end could equal or eclipse those numbers in the 2021 season alone.

Smith, the 50th overall pick in 2019, will certainly have a chance to leave his imprint on the Vikings offense. With Rudolph now with the Giants, Smith is clearly viewed as the Vikings No. 1 tight end on the roster.

Still just 22 years old, Smith drew rave reviews from coaches for his approach this spring.

"Irv has come back in phenomenal shape. He's really been working at it since we last saw him in the building," Vikings Offensive Coordinator Klint Kubiak said in May. "But I don't want him to do anything different. I want him to be himself.

"And now he's going to have more opportunities, and I'm excited to see what he does with it," Kubiak added. "But I just want to push him in the day-to-day … to get better at a few things every day and just get some aggregate gains and put those forward toward the payoff in the season."

Smith said he focused on his diet in the offseason, and appears to be primed for a breakout in his third season.

"Obviously [my] workload's going to be increased," Smith said. "I'm working hard, but it's obviously going to keep going up and keep going up, so for me, I just take every role for what it is and just try to make the most out of every opportunity.

"Coach Zim's done a great job, obviously, of implementing me these past two years," Smith added, "but definitely I feel like my role will increase."

What does Tyler Conklin have in store for Year 4?

While Smith will certainly draw more attention from opposing defenses, they will certainly need to account for Conklin, too.

The former fifth-round pick has grown into a reliable player with hard work and determination, and can now be viewed as somewhat of a secret weapon in Minnesota.

Conklin had 19 catches for 194 yards and a score in 2020. But he really thrived at the end of the season with 15 catches for 168 yards in the final four games when Rudolph was out with an injury.

Smith said this offseason that he and Conklin have the potential to be among the league's top duos at their positions in 2020.

"I'm very, very excited about me and Conk' together out there," Smith said. "Conk is a great player, great guy on and off the field. I feel like the tight end, you want to be able to move and not only be a threat in the pass game but in the run game as well.

"I feel like me and Conk' are one of the best duos at doing that," Smith added. "With that being said, I'm very excited about me and him playing together and having this opportunity."

Conklin is entering the final season of his rookie contract, so another strong year could set him up for a pay bump. But it's clear after three seasons that he has worked himself into one of the most respected players on the roster.

Who emerges as the third tight end?

Kubiak is entering his first season as the Vikings OC, but don't expect the offensive scheme to change much from what the team has done in recent years.

That should equate to the continued use of multiple tight end sets, which means the third player behind Smith and Conklin will be a key piece of the offense.

There is plenty of intrigue regarding that spot.

Brandon Dillon is the more experienced of the three tight ends after Smith and Conklin. He is entering his third season in Purple. The former undrafted free agent spent most of the past two seasons on Minnesota's practice squad after making the roster for Minnesota's 2019 season opener.

He has flashed in the past two training camps and the 2019 preseason and could cement a roster spot with another strong performance in the coming weeks.

Zach Davidson was a fifth-round draft pick this spring out of Central Missouri (Division II). He has perhaps one of the most unique backgrounds on the team, as he was a tight end and punter in college.

Davidson has considerable length at 6-foot-7 and is listed at 243 pounds, but could also need time to adjust with the jump from Division II to the NFL.

The other rookie tight end on the roster also played at a Division II school. Shane Zylstra had a prolific career as a receiver at Minnesota State, Mankato.

Zylstra showed receiving skills that helped him become the school's all-time leader in career receptions (227), receiving yards (4,297) and touchdown catches (54).

Smith and Conklin will surely get plenty of work this summer, but the battle between Dillon, Davidson and Zylstra for the third spot will be one to watch.

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.