GREEN BAY, Wis. -- Mike Pettine and Matt LaFleur wouldn't seemingly have much in common.

Pettine is old-school: a 53-year-old former high school coach with a hardcore defensive mindset.

LaFleur is the new wave: a 39-year-old offensive hotshot from the Sean McVay-Kyle Shanahan innovation machine.

Yet nine months into their partnership and six games into their first NFL season together, it looks like a match made in a film room. The Packers stand 5-1 and atop the NFC North heading into Sunday's game against the Oakland Raiders not because LaFleur rejuvenated Aaron Rodgers and the offense -- although signs suggest that's happening -- but more so because of Pettine's side of the ball.

And perhaps because they're more alike than anyone thought.

Among their shared qualities is self-deprecation.

After the Packers' defensive-minded 10-3 win over the Chicago Bears in the season opener, LaFleur was asked how much input he's had on the defensive side of the ball.

"I didn't want to mess with those guys too much," he said at the time.

This week, after the Packers' defense came up big in holding the Detroit Lions to field goals each time the offense turned the ball over, LaFleur was asked something similar.

"I'm trying not to mess with them too much on the defensive side," LaFleur said.

Then, there's Pettine, who shortly after he was retained was asked how his past experience as a former NFL head coach with the Browns could help LaFleur.

"I have a thick book on what not to do," Pettine said at the time.

One degree of separation

LaFleur and Pettine never worked together before this season.

But upon closer inspection, there was far less than six degrees of separation.

"We're more like one degree of separation," Pettine said recently in an interview with ESPN.com.

Pettine hired LaFleur's brother, Mike, as a coaching intern with the Browns in 2014. That same season, Shanahan served as Pettine's offensive coordinator. Both before and after Cleveland, Shanahan worked with Matt LaFleur.

"I had heard a lot of good things about Matt," Pettine said.

For LaFleur, he called it "a no-brainer" to keep Pettine.

"I've gone against his defenses in previous stops and they present a lot of challenges for an offense," LaFleur said. "He's going to give you a lot of different looks. I think it's an illusion of complexity a little bit where it's a little bit easier for his guys, but it's harder on an offense. And I thought there were signs of really being able to progress in Year 2 of a scheme.

"Also, my brother had worked for him. Kyle Shanahan, who I'm really close with, had worked for him in Cleveland. And they gave him both two thumbs up in terms of the person, the character, and that's one area that I did not want to compromise on, was the character of our coaches. And he checked out."

Unfinished business

Former Packers coach Mike McCarthy hired Pettine in 2018 after nine years with Dom Capers as coordinator.

Pettine, who hadn't coached since the Browns fired him in 2015, made modest gains in his first season; the Packers jumped from 22nd overall to 18th but couldn't come up with game-changing plays in the form of third-down sacks or takeaways.

"I felt like it was just kind of unfinished business," Pettine said. "The investment that you make in Year 1 of trying to build that foundation, and then to have to pull those roots up and go somewhere else and redo that Year 1 -- not saying I just didn't want to go through that Year 1 again, but just everything about here: the culture, the town. I'm a small-town guy. I just need to know how to get to work and a couple of nice restaurants and, if I need to get out of town, where's the airport, and I'm good to go."

While the ranking hasn't changed much -- the Packers rank 21st in yards allowed per game -- their turnover numbers and sack rates have spiked. They already have 11 takeaways (four fewer than all of last season, when they tied for the third-fewest in the league) and nine sacks on third down (nearly half their total for all last season). They rank ninth in sack rate and 12th in pressure rate and have done it without Pettine blitzing like mad. Their blitz percentage of 23.1% is below the league average of 26%, according to ESPN Stats & Information research.

Even their suspect run defense was seemingly fixed before Monday night's win over the Lions.

Of course, an influx of talent has helped.

Pettine and general manager Brian Gutekunst had a frank conversation shortly after the season about the need for defensive upgrades, and Gutekunst's signings and draft picks reflected it.

The Smiths, Za'Darius and Preston, have combined for 13 sacks (the most by any duo in the NFL this season) and half of their season sacks have come on third-down plays. The revamped safety position, with free agent Adrian Amos and first-round pick Darnell Savage Jr., has stabilized the secondary.

Pettine, too, might have been part of the impetus for some of those players to come to Green Bay.

"You know he was at Baltimore, so once I first got here I think I made a phone call to [former Ravens outside linebacker Terrell] Suggs to ask him about what type of coach was here," said Za'Darius Smith, a former Raven. "He's like, 'Z, man, you're going to have a lot of fun with Coach Mike Pettine.'"

‘We earned it'

It's the first time in Pettine's career that he's been older than his head coach.

McCarthy is two years Pettine's elder. In Baltimore, where Pettine broke into the NFL in 2002, Brian Billick was significantly older. With the Jets, where Pettine first became a defensive coordinator in 2009, Rex Ryan was older. With the Bills, where Pettine worked for one season in 2013, Doug Marrone was older.

In some ways, it's the new normal. According to a report by the Washington Post, nearly half the NFL teams (14) have a defensive coordinator who used to be a head coach. Ten of them, including Pettine, serve for head coaches who call offensive plays (like LaFleur does).

"That's the beauty of football and just dealing with the players and the coaches, nobody cares about that," Pettine said. "It's just, ‘Can you do your job? I'm not worried about the life experience, just is this guy a quality guy to work for?' The age part of it, just like the players in the locker room, whether it's racial, religion, it's all about football."

Pettine indicated LaFleur has a greater interest in the defense than he has let on.

In the spring, LaFleur sat in on the defensive meetings and watched Pettine teach and reteach his system to the players. And like McCarthy, LaFleur encourages across-the-hall communication between coaches on the other sides of the ball.

Pettine said that during game weeks, he and LaFleur meet several times to discuss the plan. Pettine's office is situated just down the hall from LaFleur's on the third floor at Lambeau Field, so, Pettine said, "he stops in on a fairly regular basis, and usually when he's coming up the hallway, either on his way to his office or coming back out, [because] I'm kind of right at that intersection, so it's really easy to pop in."

But there's an autonomy to Pettine's job, too.

"It's certainly helpful, and you're very appreciative of Matt having that trust in us," Pettine said. "And I think we earned it."