The ninth-year veteran has seen a number of systems, styles and subtleties, enough to know what will and won't work at football's highest level.
And Posluszny believes Jacksonville has something unique going on - a culture worth defending - under third-year coach Gus Bradley. It's helped the Jaguars get through an unprecedented overhaul, the kind of project seen more from expansion teams than entrenched franchises.
''It's not like this everywhere,'' Posluszny said. ''If we want to keep this, at some point we need the results on the field. We have to win. We need to realize that this environment is a special, special thing, and we need to do everything we can to protect it.''
The Jaguars are 10-31 during Bradley's three seasons, including 3-6 heading into a game Thursday night against AFC South rival Tennessee (2-7). It's hardly the kind of results that prove they're headed in the right direction. But everyone in the locker room, everyone in the building and most importantly general manager Dave Caldwell and owner Shad Khan believe the franchise is trending upward.
''We've all stuck together, so it's made it survivable,'' Caldwell said. ''We've had a lot of conviction in our vision and our belief of how we wanted to do this and the process, and we haven't wavered from it. We're not stubborn about it, but we haven't wavered from how we want to do it. It's been challenging. It's been really challenging, but I think greater days are ahead for sure.''
The Jaguars are one game behind co-division leaders Houston and Indianapolis, and have the league's most favorable schedule down the stretch. Atlanta, which has lost three of its last four, is the only team with a winning record left on Jacksonville's schedule.
So making the playoffs is not quite the pipe dream it's been for the Jaguars in recent years.
Getting there surely would silence some of Bradley's critics. It also would help protect the culture Bradley has spent three years building in Jacksonville.
''It's not like anything I've ever been around,'' said guard Zane Beadles, who spent four years in Denver before signing with the Jaguars in 2014. ''I fully believe in it. I think there is a learning curve with it for how to work within the culture and still kind of maintain that edge and still maintain what you need to be a good football team and a good football player. On the back end of it, the ceiling is so much higher.''
The culture Bradley has in place is hard to explain.
It starts with his infectious smile, positive energy, passion and enthusiasm. It includes Bradley taking a personal interest in everyone's lives. And it extends well beyond personalized milkshakes, music during practice and yoga and massages for players.
It's also more complicated than Bradley's ''get better'' motto or his belief that players and coaches shouldn't let external sources influence internal feelings.
''It's a competitive atmosphere with a head coach whose only goal is to maximize everything that you have as a player and to get your absolute best out of you,'' Posluszny said. ''And he makes it personal. It's not like that everywhere.''
There's no yelling or screaming, and Bradley remains upbeat no matter the outcome.
He's Pete Carroll 2.0.
''It's not about wins and losses all the time,'' veteran tight end Marcedes Lewis said. ''We really believe in the process. If you believe in the process, then you understand that good times are going to come and results will go your way at some point. If you're somebody that has a fixed mindset who thinks that it's all about winning, then you're going to do anything you can to get your results no matter if you're doing the wrong thing or being selfish or whatever.
''As long as you get your results, that's all that matters to you. And that's now how we think in this organization.''
Just about everyone in Jacksonville agrees, and they believe the Jaguars are on the verge of something special.
''We haven't had success, but we're in a position to win,'' Posluszny said. ''The final step we have to take is figuring out a way to get over that last hump. Instead of saying, `Man, we should have beaten them,' it's going to be, `We did everything that we needed to do to win.'
''That's where we're at right now. That final hurdle and then things will really take off.''
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