Papalii, 23, is the newest addition to the group dubbed "Club 82", which also includes Croker, Josh Hodgson, Sia Soliola and Shaun Fensom.

Croker knows the benefits of being handed a leadership role at a young age after taking over the Raiders' captaincy last year when he was 24. "Everyone's different, but I feel it did for me," Croker said.

"You've got that little bit more expectation on your shoulders and I felt it helped me a lot and made me mature a little bit as well.

"I know [Papalii] is quite mature as it is, but I'm sure his game will go to another level as well."

Papalii has played 104 career games after making his first-grade debut for the Raiders in 2011.

He has played eight Tests for Australia, including four games at the 2013 World Cup, and four State of Origin games for Queensland.

Papalii is one of a number of key Raiders players, including Blake Austin, Aidan Sezer, Jack Wighton and Josh Hodgson, who are signed until the end of 2018.

At one stage he was looking to go elsewhere when he signed with Parramatta early in 2013, but he reneged on the deal to remain in Canberra.

Papalii was also cautioned after he and then teammate Anthony Milford were drinking two days before their round 25 game against the New Zealand Warriors in Auckland in 2013.

Papalii struggled with his form at the start of last season, which led to him losing his spot in the Queensland team.

But he turned it around to regain his place in the Maroons side for the series-clinching victory in game three.

Croker said Papalii's experience in the representative arena made it the perfect time for him to have increased responsibilities.

"He's obviously got the experience there even though he's a young guy, so I think it's good for Josh," Papalii said.

"He has led for the whole pre-season, I think his weight and his body fat's have been as good as they've been.

"He's leading by example off the field, so it's a good time for him to step up as a leader on the field as well."

Fensom, 27, has also taken on a bigger role, filling the void left by prop David Shillington's move to the Gold Coast Titans.

With 125 games of first-grade experience and two Mal Meninga Medals to his name, Fensom has embraced the opportunity to lead from the front.

"Over the previous seasons I've been trying to improve my leadership around the club and this year I've taken it to the next level," Fensom said.

"We've got a good group of guys helping [Croker] out with the captaincy in the Club 82 group.

"You forget how young [Papalii] and [Croker] are, and you have me and Sia who are bit older, so it's a good mix of young and old."

SATURDAY: Canberra Raiders v Penrith Panthers at Canberra Stadium, 3pm. TV: Live on Fox Sports. Tickets at Ticketek