GREEN BAY - There's serious Tramon, and there's smiling Tramon.

Both sides of cornerback Tramon Williams have been welcomed in their return to the Packers' locker room and were on full display last week after the team's open OTA practice.

He was serious Tramon when discussing the role he's taking as the veteran leader of an otherwise young cornerback room.

It's a responsibility he cherishes, knowing he's now in the position Charles Woodson and Al Harris were for him back when he was trying to make his way as an undrafted player more than a decade ago.

Then he's smiling Tramon when talking about being back in Green Bay after three years away, where it "feels like home," and he's even returning punts in practice just for the heck of it.

"It's still there," a grinning Williams said of those special-teams skills, which led to his first big play in an NFL game, a 94-yard return of a pooch punt vs. Carolina at Lambeau Field in 2007.

"Coach (Ron) Zook, I talked to him and he made a comment, 'T, I was watching some old film, and you didn't tell me you were that good of a punt returner.' I said, 'Coach, I'm 35. Don't get no ideas.'"

And then came the hearty laugh. Yeah, Williams is definitely feeling at home back in Green Bay.

The Packers are glad to have him, too. With second-year pro Kevin King plus rookie draft picks Jaire Alexander and Josh Jackson potentially slated to play a lot of snaps at cornerback in Mike Pettine's defense in 2018, a role model like Williams can be invaluable.

King has been described as "in Williams' back pocket," learning everything he can while his on-field work is currently limited following offseason shoulder surgery. The other young corners also naturally gravitate toward a guy who's been to a Pro Bowl, made big interceptions in playoff games, and won a Super Bowl, all after starting as a practice-squad pickup by the Packers back in 2006.

"I said it walking off the field (Monday), the biggest difference on the back end is (number) 38," quarterback Aaron Rodgers said. "When he showed back up here, he is, as of right now in my humble opinion, the best on that side of the ball, and you want your best players to be the best guys in the locker room, and there's nobody better than Tramon. It's great having him back."

Defensive pass-game coordinator Joe Whitt, who was Williams' position coach from 2009-14, labeled him the "ultimate pro" and compared his presence now to that of Woodson when Whitt first took over the cornerback room nine years ago.

That's heady praise, and while there's still plenty of spring in Williams' 35-year-old legs, he's the first to admit his smarts have led to his longevity. The studying, the mental edge and the on-the-fly adjustments are the things he can teach younger players as they watch him jump routes and deflect passes in yet another OTA workout.

"Experience. You see different things over time, and you just understand what you're going to get," Williams said. "Young guys don't understand that right now. They're making plays, and they're making plays because they're talented. But they're not making plays because they know what's going on.

"When you know what's going on, it becomes a lot easier, and that's really where I'm at right now."

Williams also seems to have struck the right balance between mentor and competitor. He wants to play, and he knows the young guys are here for the express purpose of replacing a veteran like him. He said no one has to "explain" the competition part of it.

But he also wants to win, saying he has "unfinished business" in Green Bay, a reference at least in part to his last Packers game, which ended with an NFC title slipping from his grasp in Seattle 3½ years ago.

"I can't say enough as to what he brings to the DB room," Pettine said. "As coaches we can only get a guy so far, whereas I think when they have a guy sitting next to them that's played, that's been through it, that knows how to prepare, that knows how to get through a long season … I think the two rookies, they couldn't have asked for a better veteran to be in the room."

The fact that he played for Pettine in Cleveland is a bonus, but his leadership has less to do with the scheme than the bigger-picture, be-a-pro elements because Williams confesses the playbook isn't difficult to learn.

It wasn't for him when he joined the Browns in 2015, though experience again was a factor, having already played in two systems (for defensive coordinators Bob Sanders and Dom Capers) over his first nine years in Green Bay.

"I felt that he had a lot of simple things you didn't really have to think about, but he got so much effect out of them," Williams said of his introduction to Pettine's scheme. "Guys are out there playing like they already really know the defense, like they've known it for a couple years now.

"We picked up the defense like that (in Cleveland) and guys were playing fast. That's the thing I love about Pettine's defense. You can just come in and play fast right away, and it has so much variety to it without being complicated."

Williams is certainly not a complicated guy, serious or smiling.

He loves the opportunity in front of him now that he's back in Green Bay after an impressive one-year stint in Arizona last year, but walking back into the Packers' locker room provided a stark reminder of his humble beginnings as a pro.

"It can't leave," he said. "That's one of the things that keeps you hungry, understanding where you were. You don't want to go back there, but understanding where you were and where you came from, and that keeps you working."

It keeps him leading the way for the next generation of Green Bay cornerbacks, too.

"I like them. I like what we're doing right now," he said. "It's been fun out at practice. We have the potential to be special.

"Potential."