JACKSONVILLE – He has the look and feel of a player about to break out in a big way.

But first things first.

That's where Myles Jack is in Jaguars 2018 Training Camp – the first things first part – and the first thing he's trying to do as he prepares for what appears to be his breakout NFL season is make sure he's as prepared as possible for a modified, important role.

"Full-time job, full-time responsibility," Jack said following a two-hour, 40-minute practice Sunday at the Dream Finders Homes Practice Complex.

And that's a good way to describe Jack's situation during this year's training camp.

It's a good way to describe what he's going through mentally.

It's a good way to describe his approach this August.

Jack, a third-year veteran who took on the look of a rising star with standout postseason appearances last season, isn't moving to a completely new role this season. But he's adding a lot of responsibility, and he's doing what he did part time last season on a full-time basis now.

Jack played strong-side linebacker in base situations last season, and played middle linebacker in nickel situations. He was on the field on 97.8 percent of the plays, but he was only responsible for calling the defense as the middle linebacker in passing situations.

The offseason retirement of middle linebacker Paul Posluszny changed that.

Now, Jack will play full time in the middle. That means calling the defense on all plays, base and nickel.

"Last year, when we were nickel I had to be vocal in everything, but when we went to base I could lean on Poz to do the communication," Jack said. "Now, I'm out there talking all day and going home with a raspy voice and coming back and doing it again. That's just a part of the job."

The move had the feeling of inevitability after Posluszny's retirement, and it appears Jack is making it successfully.

"I really think that he is a heck of a player," Jaguars Head Coach Doug Marrone said Sunday. "I think he has a good command. He runs well. He is a physical player. I think he has improved from where he was at this time last year. I felt that he played very well last year, but I really think we can get more out of him. I think that he expects more out of himself."

Jack has drawn praise from teammates throughout training camp. And to watch Jack is to know few NFL linebackers have his combination of speed, suddenness and athleticism. Teammates during camp also have talked of Jack playing more instinctively, the mark of a young player gaining the experience to reach his full potential.

But as the middle linebacker Jack also wears the headset that communicates with coaches on the sideline. And the process of getting that information from his head to his teammates is his main focus entering the season.

"That's the main thing, being a young Mike (middle linebacker) in the NFL – it's just being able to communicate – and over-communicate at times," Jack said.

The key, Jack said, is to get teammates "to see everything that you see."

"That's the main thing, it's just talking," he said. "There are times when you're playing Mike when you're exhausted but you still have to talk to everybody else so other people can be in their own zone. That conditioning is there, and I'm very excited about it."

Jack talked on Sunday about the need to be calm amid chaos and being able to have poise "when things go to haywire."

"You're like a quarterback out there," Jack said. "You have to approach it as such."

That's undoubtedly how Jack has approached it – and not just in camp. Marrone talked Sunday of Jack's offseason approach.

"He's been here pretty much the whole year," Marrone said. "I have seen him. He was here in the offseason and working hard. I think he looks good. I think he is ready to have a good year."

The consensus around the Jaguars is that last quote from Marrone could be an understatement. Both safety Tashaun Gipson and cornerback A.J. Bouye went out of their way last week to mention Jack when asked about the talent level on the Jaguars' defense.

"He's going to be one of the best linebackers in the league for years to come," Gipson said.

Bouye agreed, saying "I think he does not get enough credit. 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."

So, yeah: Jack's 2018 training camp is a matter of first things first.

But once that first thing is done, the feeling around this team is Jack could break out in a big, big way.