GREEN BAY — One day during the offseason, Green Bay Packers teammates Julius Peppers and B.J. Raji were playing pickup basketball when Peppers decided to go for it.

Raji, the Packers’ nose tackle, is six years younger and 50 pounds heavier than the 35-year-old pass-rusher. But Peppers, at 6-feet-7 at 287 pounds, used to spend his winter months at North Carolina as a walk-on forward for the Tar Heels. That was years ago, but here he was anyway, charging through the lane and trying to dunk on Raji.

Peppers went up, but the ball seemed to catch on the rim. It bounced back toward the floor, and Raji laughed but also felt relief. “He could’ve easily got me,” Raji would recall months later, straddling the line between polite teammate and proud man who’s not easily dunked on.

Peppers, who’s now the NFL’s fourth-oldest defensive player, didn’t like it. There was no getting around his age, but it had never seemed to hold him back. He could still turn the corner and get after quarterbacks; his speed, instincts and versatility — he had seven sacks and two interceptions last season — still make him a nightmare matchup for offenses. Even in his 14th year, his 6 1/2 sacks are tied for 11th in the league.

He thought about the failed dunk, how his body had let him down, and tried to shake it off. Used to be Peppers would pity the other players who’d relax a month or two after each season before firing up the engine again. Peppers never needed that kind of runway to get in game shape. He’d take off three or four months, barely doing anything until it was time to report for minicamp in late spring. Other veterans lamented needing two or three days just to recover from the rigors of a game; Peppers would spring from bed the next morning, ready to suit up again.

But it was his genes as much as his youth. Peppers didn’t need the gradual transition from zero to 60 that most players required. More than that, he never seemed to get injured. He was, even at the highest level of one of the most grueling sports, seen as a rarity.

“I’ve always looked around,” Peppers said last week in the Packers locker room, “and pretty much knew that I was built a little different.”

Peppers, who for most of the last decade was among the league’s most disruptive players, recorded double-digit sacks in eight of his first 11 seasons. Earlier this season he brought down San Francisco’s Colin Kaepernick to enter the top-15 all-time for career sacks. Carolina’s Jared Allen and Denver’s DeMarcus Ware are the only active players ahead of Peppers and his 132 sacks.

The seasons passed, and Peppers found himself fitting in with new teams — he left the Panthers, who drafted him No. 2 overall in 2002, to join the Chicago Bears in 2010, before signing with Green Bay before the 2014 season — and new schemes. A defensive end for the first part of his career, he’s now a pass-rushing outside linebacker for the Packers, who have him under contract through the end of the 2016 season.

Despite the changes, he said, he mostly maintained his routine. If he did work out during offseasons, it was as much out of boredom as any investment toward longevity. He passed on the heavy weights that make up the typical defender’s offseason regimen, preferring exercises that emphasize mobility and biomechanics. Peppers, still one of the league’s most graceful players at his age and size, found himself working not on explosion and brute strength but flexibility, leverage and body position.

“You see him in the offseason — he’s smooth,” Raji said. “In this business, if you move well, there’s less chance of injury. And generally when you’re injured less, you’re going to feel better more times.”

Peppers has never suffered a broken bone nor required surgery. In a sport and league in which absences are accepted as a grim and unavoidable reality, Peppers has somehow missed two games since 2003, his second NFL season.

“He’s, like, an anomaly,” Raji said, shaking his head.

Last January, after the Packers blew a double-digit, fourth-quarter lead to Seattle in the NFC championship game, Peppers settled in for his usual offseason break. This time he added shaving to the things he’d stash for the winter, and soon a beard was thickening and creeping down his neck. He didn’t care much for the gray strands on his chin, but when his girlfriend asked him to get rid of the damn thing, pointing out that it masked his still-youthful face, he chuckled and refused.

“It’s wisdom,” was his response, at least for a while. “Experience.”

When the preseason began he found himself occasionally needing to loosen up before practices in the hot tub, and mornings started more slowly than they once had. These were new developments, but Peppers — who had never felt subjected to time’s tightening grip — tried to ignore them.

“Certain days,” he said, “you wake up and you’ve got to get it going a little more than others. But for the most part, I’m able to just get up and get it rolling, rolling pretty good.”

Then he tried to dunk on Raji, and that didn’t go as planned. Taking care of his body now seems like a year-round responsibility.

“I guess that’s a little different,” Peppers said.

It had happened quickly, and if anything Peppers was relieved to see the new season arrive; on the field, of all places, is where Peppers still seems youthful. He is a pleasant surprise in this environment, and as long as he doesn’t seem old, maybe he really isn’t.

Early last week Peppers saw himself in the mirror and decided it was time for a change. The gray hairs were longer now. There were more of them. He took a razor to his face for the first time in nearly 10 months, leaving only a goatee, watching as the beard and maybe the years washed away for at least a while longer.

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