GREEN BAY – The first individual period of organized team activities was the most jarring for Kenny Clark.
A byproduct of the Packers' looming switch to a 4-3 defense was the expansion of the defensive line from a quaint group of seven or eight to a packed house with the edge rushers moving into the room.
That new landscape hit Clark the first time the defense broke into groups this spring.
"When we do drills, I'm like, 'Damn.' We've got like a big group of defensive linemen now," Clark said. "It's going to be a lot different, but with this system, you've got to play like that."
Green Bay's defensive front has been fused together under new defensive coordinator Jeff Hafley with former pass-rush specialist Jason Rebrovich taking up the mantle as defensive line coach.
The shift from 3-4 to 4-3 is mostly semantics, though the primary responsibilities of the defensive line will be different from those Clark became familiar with during his first eight seasons in Green Bay.
In its simplest description, the defensive line will play more of an attack-and-react style rather than the read-and-react approach previous Packers 3-4 schemes have required.
While Clark made three Pro Bowls in eight seasons working out of that alignment, Green Bay's longest-tenured veteran is excited for the change. Having played in both a 3-4 and 4-3 at UCLA, Clark feels it should be a seamless switch.
"It's one of things where all my career I've been kind of been playing this way, but in more of a controlled way," said Clark, whose 34 career sacks are most for a Green Bay interior defensive lineman since 1982.
"Now this is giving us a chance to shut all that other stuff off … just use your ability, go up the field and be disruptive. I just think with my get-off and how I am, I think it's going to suit me well."
Clark is conditioning his body for the new scheme. After cutting to 305 pounds last year to play more 3-4 defensive end, Clark wants to dip under 300 for the first time since high school to improve his speed and explosion.
That's the direction the position has turned over the past 10 years. Listed at 6-1, 285, Aaron Donald helped redefine what it means to play defensive tackle during the course of his soon-to-be Pro Football Hall of Fame career.
Clark trains during the offseason with two of the game's best sub-300 defensive tackles, DeForest Buckner and Arik Armstead, who both were successful in San Francisco's attacking 4-3 front.
"I would check up with them and see what it's like playing in that," Clark said. "I always wondered what it was like, but now that I'm in it, I see how they made so many TFLs and all those plays they were always making. It all makes sense. They were really just cutting it loose that whole time."
On the opposite end of the spectrum, second-year defensive lineman Colby Wooden bulked up to 290 pounds and incorporated yoga in preparation for the new defense after playing his rookie year at a listed weight of 273.
The changes Wooden implemented this offseason caught the attention of Head Coach Matt LaFleur, who commented after last Tuesday's OTA practice that "he's looked great up to this point."
Wooden, who had 17 tackles and a half sack as a rookie, feels he has a good grasp of what Hafley's defense will entail after playing in a comparable defense for two years at Auburn.
"Last year we were more reading," Wooden said. "This year we're asked to just not think and go, which plays into our favor. We would get stuck on, you know, play-action. They would hold us and because we're reading, we can't get to a pass rush and so this year, we're not reading we're just going. Full stop running on the way to the quarterback."
When Packers' assistants met with the media earlier this month, Rebrovich referred to his group as the "first line of defense" responsible for disrupting things up front and creating opportunities with pressure.
The merger involves two loaded positions with Rashan Gary, Preston Smith, Lukas Van Ness and Kingsley Enagbare coming off the edge, and everyone returning on the interior defensive line.
In addition to Clark and Wooden, former first-round pick Devonte Wyatt, fourth-year veteran T.J. Slaton and second-year pro Karl Brooks will also contribute to that deep rotation.
Like Wooden, Wyatt played in both a 3-4 and 4-3 at Georgia. Coming off a 5½-sack sophomore season, Wyatt believes the philosophical shift will only help his development as it allows him to focus on one thing rather than having to account for multiple variables.
It has the 6-foot-3, 304-pound defensive lineman eying a "monster leap" in 2024. Surely, he won't be the only one with high expectations.
"The four-down front, I liked that better," Wyatt said. "I just feel like it gave me the best chance to attack, attack, attack instead of reading and reacting."
