EAGAN, Minn. — Hercules Mata'afa's rookie season was wiped out before it even had a chance to begin because of an ACL injury.

But now that Mata'afa is back on the practice field — and in the position he feels the most comfortable — he's beginning to show why he was one of the best defensive players in college football just two years ago.

Vikings Head Coach Mike Zimmer was a guest on KFAN's 9 to Noon live broadcast from Twin Cities Orthopedics Performance Center on Wednesday and told "Voice of the Vikings" Paul Allen that Mata'afa "has been the surprise of the camp, to be honest with you" during Organized Team Activities.

"Players are talking about him. He's up to 275 now," Zimmer said. "He can get out of the chutes without raising up at all, has been difficult to block. He's very active."

Mata'afa brushed the praise aside earlier this week and said he's just happy to have found a spot as a 3-technqiue defensive tackle, a position where he believes he can flourish.

"I feel like I'm at home. I'm playing where I feel comfortable at," Mata'afa said. "I'm glad I came here because I knew the Vikings would give me a shot if linebacker didn't work out for me. That's what they did, and I'm just coming here, showing what I can give the team."

Mata'afa was the 2017 Pac-12 Defensive Player of the Year at Washington State, where he set a school record with 22.5 tackles for loss to earn First-Team All-Pac-12 honors.

But he went undrafted in the spring of 2018 before landing with the Vikings as an undrafted free agent. With Mata'afa weighing a hair over 250 pounds, Minnesota tried him at linebacker during rookie minicamp.

The transition wasn't as smooth as everyone hopes, so the Vikings rotated him between defensive end and the 3-technqiue during OTAs in 2018.

But Mata'afa suffered a torn ACL in the last week of OTAs, prematurely ending his first season in the NFL before training camp.

"It's good to be back. It was pretty hard … my first full year without football since I redshirted," Mata'afa said. "I just came in for treatment every day and made sure my body was right for these moments right now."

That included adding 20 pounds to help out on the interior of the defensive line, a spot Mata'afa isn't entirely unfamiliar with.

"I played 3-tech in college, so it's not new to be me, it's just different schemes," Mata'afa said. "Getting used to the new scheme is something I'm working on.

"That's where I played all college, and it's where a lot of people told me I couldn't play coming out of college [and in the NFL]," Mata'afa added. "It feels good to be able to make my mark. I am where I am and I'm happy to be here."

Much like Zimmer, Vikings Defensive Coordinator George Edwards said earlier this week that Mata'afa has turned some heads as spring practices roll on.

"He's really embraced it. He is playing the run well, he has a good pad level," Edwards said. "His quickness and his size rushing the pass rusher is really showing up in these first couple practices.

"He ended up on injured reserve last year, and he really worked his butt off throughout last season and this whole offseason, getting him prepared to go," Edwards later added. "He has put on some good girth, and it really hasn't affected his play. So his quickness is really beneficial inside."

The Vikings have established veterans on the interior in Pro Bowler Linval Joseph and Shamar Stephen, who returned to Minnesota after spending the 2018 season in Seattle.

The rest of the group features young players such as Jaleel Johnson, Jalyn Holmes and 2019 sixth-round pick Armon Watts.

Zimmer usually isn't one to heap praise on unproven players, but he had plenty of it Wednesday for Mata'afa when talking to Allen on the radio.

"We had a kid when I was in Cincinnati named Geno Atkins," Zimmer said. "We were in OTAs and one of the quarterbacks came up to me and said, 'Do you think he can do this when pads go on?' I said, 'I don't know. We'll see,' and he did.

"That's kind of, you know, I'm not saying he's Geno, but he's so active in these OTAs," Zimmer added. "Now, the question is, 'Can he continue to do it when we get the pads on?'"

Mata'afa will get his chance to shine in two months when training camp rolls around and the pads come on.

In the meantime, Mata'afa is just thrilled to be playing football again, all while keeping his goals modest.

"Making the team — that's my first goal," Mata'afa said. "From there, it's winning games. That's all I'm here for, to help the team."