GREEN BAY – For all the talk about the unveiling of the Packers' new offense come Thursday in Chicago, the defense won't exactly be old and stodgy.

At least five fresh starters and a ball-attacking mentality will be featured in defensive coordinator Mike Pettine's second year. The outside linebacker and safety positions got makeovers in the offseason, and the overriding message to the unit was generating turnovers is a top priority.

"This year we're very hungry," said fourth-year defensive lineman Dean Lowry, who signed a contract extension early in training camp. "This is the hungriest I think we've been on defense since I've been here.

"I would say we've got a great cohesiveness, too. We're always watching film together, we're always talking football. Our life revolves around it."

The personnel changes begin with free-agent outside linebackers Za'Darius Smith and Preston Smith on the edge, with first-round draft pick Rashan Gary primed to play plenty as well. Safety Adrian Amos also came to Green Bay during free agency, joined by another first-round pick in Darnell Savage in the back end.

That haul of new talent is being added to a solid cast that became well-versed in Pettine's system a year ago, including defensive linemen Kenny Clark and Lowry (who will take many of the departed Mike Daniels' snaps), linebackers Blake Martinez and Kyler Fackrell, and cornerbacks Jaire Alexander, Kevin King, Josh Jackson and Tramon Williams.

Add in the emergence of other young players like defensive linemen Tyler Lancaster and Montravius Adams, cornerback Tony Brown and safety/hybrid linebacker Raven Greene, and the Packers feel they have a group ready to continue the climb in the league rankings that modestly began under Pettine a year ago.

Pettine's biggest talking points in 2019 have been tackling and takeaways. The former looked a tad shaky early in the preseason, but the starters weren't playing much anyway. A handful of turnovers came, too, but again largely without the starters on the field.

Pettine believes the latter can carry over because of the habits that have been created in practice, getting it "ingrained" in the players to be aware of the ball at all times.

"I feel like we're together and we're coming together," Amos said. "That happens week by week. We have a lot of speed on the defense, we get to the ball, and we have to prove it on Thursday.

"Tackling is important and takeaways will erase a lot of mistakes. If we can execute in both areas, then we'll be great."

There are some measures of uncertainty, though. Oren Burks' injury leaves a question as to who will get the majority of the snaps at inside linebacker next to Martinez between rookie seventh-round pick Ty Summers and Greene, a sub-package regular.

Also, the only player on the defense with a double-digit sack season to his credit is Fackrell (10½ last year), but the Packers are counting on the Smiths and Clark to now be hitting their prime.

Last but not least, King has returned to practice this week after being out since Family Night with a hamstring injury, and Pettine doubted anyone could play a whole game after missing that much time. The Packers are glad to have King back, but they'll be careful early on.

"I gotta get back out there and get that camaraderie with those guys, but from where I was standing everything looks good," King said. "The sky's the limit. A lot of new faces, but when we're out there everybody's pretty much in tune."

The Smiths, Amos, Savage, Gary and perhaps Summers will all be making their Green Bay debuts on Thursday night in Chicago. For the latter three, it'll be their official NFL debuts as rookies.

Their goal? To stay loose.

"I don't get nervous anymore, honestly," said Savage, who switched his jersey number this week from 26 to 21. Greene also changed his from 36 to 24. "I feel like when you start getting nervous and you start making things larger than they are, you play tight."

If there's anyone with a little extra emotion going into this one, it would be Amos, who played his first four pro seasons with the Bears and is returning to Soldier Field right away in a new uniform.

The two NFC North rivals actually swapped starting safeties, with Amos' predecessor in Green Bay, Ha Ha Clinton-Dix, now starting for the Bears.

"I expect there to be feelings when I come out (of the tunnel)," Amos said. "I know I have to be prepared to take a deep breath and play football."

It's finally time to do just that. This Packers unit has plenty to prove, but the belief in what the group can become is there.

"I think it's high," Martinez said. "It's something we've been talking about throughout preseason and just harping on that we can be special.

"It's just working every single day to get there, because it's one thing to talk about it. It's another thing to go out there and do it."