JACKSONVILLE – Whatever his role, Paul Posluszny said he'll embrace it.

For the Jaguars' longtime starting middle linebacker, that now means embracing a move he called "the biggest challenge of my career."

Posluszny, the Jaguars' starting middle linebacker since 2011, will move to the strong-side linebacker position. Myles Jack, a second-round selection by the Jaguars in the 2016 NFL Draft who started 10 games at the strong side last season, will move to middle linebacker.

Posluszny revealed the change soon after being told of the plan Tuesday, the second day of the Jaguars' offseason conditioning program.

"It will be a change, but that's going to be what's best for the team, so we'll give it a shot," Posluszny said.

Posluszny, an 11-year NFL veteran who said he last played outside linebacker while at Penn State University, joined the Jaguars as an unrestricted free agent from the Buffalo Bills shortly before the 2011 seasons. He started 84 of 96 possible games in six seasons, including 16 in 2011, 2012 and this past season.

Posluszny long has been considered a Jaguars defensive leader, and his teammate on the linebacker corps – weak-side linebacker Telvin Smith – praised the veteran's response to the move.

"Me and Poz, we've grown close over the past three years; he's probably one of the closest guys I have when it comes to being on the field," Smith said. "It's going to be tough, but when he accepted it I accepted it.

"I appreciate him because once again he's not a selfish person, as you all can see. If he said that's going to make the team better and help us get to where we need to go, then I'm with him all day."

Posluszny, one of four players made available to the media Tuesday, was candid about the difficulty of the move.

"For 10 years I've played middle linebacker," Posluszny said. "My entire perspective of how to play football in the NFL, my entire identity, has been that. Now, that's not the case."

Posluszny led the team in tackles last season with 133 and also registered eight tackles for loss, but team officials had talked throughout the offseason of needing Jack – widely considered one of the elite talents in the '16 draft before a knee concern caused him to slip to the second round – to be a three-down player.

"We've seen what he can do in college, and we've seen spurts of what he can do [in the NFL]," Smith said. "We're all looking forward to seeing him out there."

Posluszny said he views the change more about what he didn't do last season than the team needing to make a move for the future.

"The decision was made and they said this is going to be what's best for the team, and that's great: if it's going to help us win, it's going to help us win," Posluszny said. "I look at it and say, 'I didn't play at a high enough level to keep that job.' It's my fault, and I don't have anybody to blame but myself. If I would have played better then maybe we wouldn't be having this conversation, but that's not the case. Moving forward, I'll make the adjustment and do the best job I can.

"I want to know I have control over my destiny, so if I'm not able to play that spot it's because I didn't play well enough. That's how I'm able to wrap my mind around it."

Posluszny typically stayed on the field in base and passing situations last season while Jack at strong-side shared time with veteran Dan Skuta with both Skuta and Jack typically off the field in nickel situations. Posluszny said he expects the major change to involve playing closer to the line of scrimmage as opposed to being what he called an "off-the-ball" linebacker.

"Sam [strong-side linebacker] will be on the ball more – lining up on a tight end, which I've never done before," Posluszny said. "That will be a challenge."

Posluszny said the plan for next season is to have the best two linebackers stay on in the field in nickel situations.

"If I'm not one of those two guys, that's fine," Posluszny said. "Whatever we need to do win, let's do it. Let's be honest. That's the most important thing. If I'm not good enough to stay on the field, keep someone else on there so we can win."

Posluszny said his objective now is to "be the best Sam linebacker in the NFL."

"I just want to win," Posluszny said. "If they say this is what's best for the team, then let's do it. It will be a new challenge. It will be exciting: learning a new position, learning techniques, doing things on the field I've never had to do before … in a competitive way, you say, 'Yeah, this will be exciting: something different.' It will be a great challenge to see how I respond."