The moment they punch in, the desire to win becomes poured inside of them, but at the end of the day they unwind by sharing a laugh and make fun of each other.
But unlike a certain neighborhood Boston sports bar, not everybody knows the names of the Packers defense.
"You've got a bunch of humble guys that come into work everyday and want to get better," said linebacker Jason Hunter. "I think that's good when you got guys like that. They're fun to work with and they're fun to be with."
Entering Week 13, Green Bay was tied for fifth in the league for allowing only 16.8 points per game, yet the only group of folks that know them like their next of kin are those that live from La Crosse to Sturgeon Bay.
It's Pro Bowl quality with the star power of a ho-hum .500 team. These guys haven't allowed a 100-yard rusher since Week 4 when Vikings rookie Adrian Peterson carried it 11 times for 112 yards, which included a 55-yard scamper.
Most of them are treated like they still have the piece of athletic tape scrawled across the front of their helmet as they competed in the unforgiving summer sun for a job. Yet names that were scribbled on a helmet just a few months ago will start to be remembered more and more as the Packers continue to win.
"Our guys are making names for themselves," said defensive coordinator Bob Sanders. "They're playing extremely hard and confident and fast."
The way the defense has been able to come together so quickly this season has raised the eyebrows of some. Yet, the Packers are tied with Chicago for third in the NFL 32 sacks.
Of course, expectations were raised after the Packers missed the playoffs last year by a nosehair after winning four straight games to close the season.
"We've been expecting to play good," said defensive tackle Ryan Pickett. "Before the year started, we ended last year playing really well."
Pickett already has amassed 25 solo tackles, just six shy of his 2006 total. But, the 6-foot-2, 322-pound space eater has also gotten some help on the line.
"We're all getting that chemistry together, it's been a wonderful thing," said defensive tackle Johnny Jolly, who has blossomed into a dependable starter, but hasn't played since Nov. 18 vs. Carolina after suffering a shoulder sprain. "I mean, everyone is trying to do something for the next man alongside side of him. That's what makes us good."
"The good thing about our defense is a lot of different guys are making plays," Sanders said. "You got a lot of guys with sacks, pressures, tipped balls. You got a lot of guys in the backfield stepping up and making a play."
With Chicago suffering through a down year, that has given rise to Nick Barnett. Usually the NFC is used to seeing five-time Pro Bowler Brian Urlacher punishing opposing offenses. However, Barnett is earning all of the six-year $34.975 million contract extension he signed in April. The speedy middle linebacker already has 91 total tackles and he is on pace to finish the year with 132 – just seven off his career-best in 2005. He also has 1 ½ sacks, two interceptions and a fumble recovery, which should make him a lock to represent the NFC for the first time.
"Nick Barnett is having a fantastic year," Sanders said. "He's been solid each and every week. Certainly he deserves everything he's getting."
But these guys aren't all business. After practices and games, they'll treat the locker room like their own special hangout. In addition to the games of spades and dominoes, there is always the joker that resembles the same qualities as Norm Peterson – minus the quirky entrance and oversized bar tab.
"We always get on Jason Hunter about his pants being too tight," said Jolly with a smile. "And Kabeer's pants being too short."
Never one to take a jab sitting down, Hunter immediately has words for the stylistically uneducated.
"I'm a nice, neat, clean guy," he said. "I like to have my stuff fitted. Everybody doesn't want to have their pants hanging off their behinds. Some people like to be mature about the way they dress."
Apparently, the verbal jabs aren't going to stop anytime soon, whether at home or on the road.
"If you're 6-4, 260 pounds and wearing those tight spandex pants on the plane, we're going to let you have it," Jolly said.
The Packers are looking to clinch their fourth division title in six years and seventh in the last 13 with a relatively easy schedule the rest of the way, which includes home games against the Raiders and Lions.
"It makes me feel good that we're winning," Pickett said. "What makes me feel even better is that we're getting better every week. That's the most important thing. We're not just winning, we're improving every week."
And that's why the lunchpail attitude works so well with these guys – they're never satisfied.
"Some of things we shock ourselves," Hunter said. "We don't even know how good we can be. We're still trying to get better as a defense. We've got a long way to go. We've still got some of our best football ahead of us."
Not everybody knows every name of the Packers defense. However, it's through that cloak of invisibility that they have been able to motivate each other. The front four only weighs an average of 293 pounds, but somehow they have 30 ½ sacks and they are holding opponents to a third down conversion rate of just 45-for-142 (31.6 percent).
"I think it's kind of contagious, once we start winning we start we thinking, ‘What we can we do to get our next victory?'" said Pickett.
Playing on the same field as certain 38-year-old, who has a howitzer as a right arm, can make the defense feel about as worthless as the Deutsch Mark. But there is nothing small about holding Larry Johnson to 53 yards on 19 carries and NFL rushing leader Peterson to 45 yards on 11 carries, a week after he broke the single-game rushing record vs. San Diego with 296 yards.
With Norm to lean on, this group will continue making plays, just because they're having a ball doing it.
"We come in every day and we just have fun," Jolly said. "That's what makes it go by so easy."