JACKSONVILLE, Fla. -- Ask anyone involved with the Jacksonville Jaguars defense about Myles Jack and they'll all tell you the same thing.

He wasn't down in the AFC Championship Game.

Of course. Beyond that, they'll also tell you that the third-year linebacker is going to be the next star on a defense that's already loaded with stars.

"Myles Jack does not get enough [publicity]," safety Tashaun Gipson said. "I'll say it again: He is going to be one of the best linebackers in the league for years to come."

Jack has already flashed that potential -- especially in the playoffs -- but the Jaguars believe 2018 is going to be his breakout season and that he'll become their ninth starter to make the Pro Bowl. He might have already reached that level had NFL rules and the Jaguars' haphazard plan not stunted his growth.

Jack missed all of organized team activities in 2016 because of the NFL's graduation rule, which bars rookies whose school's semester ends after May 16 from participating in offseason activities until the semester ends. When he reported, he was put behind Paul Posluszny at middle linebacker so he could learn the entire defense.

Just before the final preseason game, he was moved to weakside linebacker; then during the season, to the strong side. The result: information overload, a tentative player, and just 230 snaps as a rookie. He was moved to middle linebacker full-time in the spring of 2017, only to be moved in August back to the strong side in their base defense to keep Posluszny on the field. In their nickel packages, Jack moved back to the middle.

It wasn't until just before the 2017 season opener that Jack felt at ease.

"Going into that first game, that's when I understood what everybody was doing to the point where I was like, 'OK, I feel comfortable,'" he said. "As the season went on it got easier."

Jack made 90 tackles, broke up three passes and had two sacks in 2017. He also recovered a fumble that he returned 81 yards for a touchdown against the Jets. A solid season statistically, but the numbers don't tell the complete story.

Posluszny was a master at making the correct checks and adjustments and communicating them to the rest of the defense. By the end of the season, Jack was doing the same. Defensive coordinator Todd Wash knew that once Jack had the communication mastered to go along with his speed, athleticism and size (6-foot-1, 244 pounds) he would be a special player.

"He can run, move, do all that, but he plays the game above the neck, which is obviously -- it's taken a while for him being a rookie, and now we're transitioning into being a full-time Mike [middle linebacker]," Wash said. "We've got a lot of stuff on his plate each and every week. Last year it was only the nickel stuff. This year he's got base and nickel, so we've seen him transition in the offseason. What he did last year athletically and how well he came along last year, we thought we always had a really good player."

That showed up in the playoffs. Jack had an interception against Pittsburgh that set up a touchdown. He forced and recovered a fumble against New England. Big plays in the biggest games.

And that has carried over into the 2018 season. Jack returned a deflected pass 32 yards for a touchdown in the season-opening victory against the New York Giants. So he's been involved in a turnover in his past three games.

"I had always wanted to play in the playoffs, and we finally got to play on TV," Jack said. "I was like, 'OK, we are playing on TV. I am going to make a play. They are going to say my name.' Now, it is kind of like, 'OK, Myles. You waited all till the playoffs to do that. Let's start the season off doing that.' Obviously staying within my reads, making your plays, but here and there go make a play like you did in the playoffs. That is what I try to do."

This week is the Patriots again, which means it's time to revisit the biggest play of his career: running down running back Dion Lewis, stripping the ball as he tackled him, and jumping up and returning it for what should have been a touchdown in the AFC title game. Except the officials blew the play dead after he recovered the ball because they believed he was down by contact.

Replays show he wasn't, and that birthed the "Myles Jack wasn't down" phenomenon. T-shirts, memes, gifs, and even local craft beers all bear that slogan. And as painful as the play is to relive -- he said he wasn't down three times in one answer -- Jack says he loves it.

"I didn't know it would go this far," he said. "I knew it was a controversial play. You guys saw the play. I slammed the ball. I was mad. I knew I wasn't down as soon as it happened. That's why I slammed the ball. I wish I didn't, because I would have kept the ball and maybe sold it on eBay 10 years from now.

"I knew I wasn't down. It's cool when people say that, because I knew I wasn't down. So appreciate it. I like it."

The playoffs was the rest of the country's first chance to see what the former UCLA standout had become, because the Jaguars didn't have a national broadcast during the regular season. Calais Campbell, Yannick Ngakoue, Telvin Smith, Jalen Ramsey and A.J. Bouye received the headlines, but Jack was as big a part of the defense's success.

"Myles Jack, I think he does not get enough credit," Bouye said. "I watch him a lot on film, and even a lot of other players talk about how much better of a defense we are because of him."

That's because Jack makes plays like chasing down Lewis from behind. Jumping in front of Steelers tight end Vance McDonald for an interception. And running down Giants tight end Evan Engram to stop him short of a first down last Sunday.

"I just want to be known as a physical football player," Jack said. "I think that's the greatest compliment you could give a defensive player. Just being physical. Obviously they're trying to take the physicality out with the penalties and everything. I just want to be a presence. I just want every game my presence was felt, whether it was a big hit, a turnover, or just a play that stood out. That's what I try to do."