But nine years after the Sydney Roosters took him in from the New Zealand Warriors as a "lost and broken" teenager, the Canberra Raiders recruit says he will channel positive energy as he deals with the hurt of being released from the Roosters.

The New Zealand Test international has joined the Raiders this week on a three-year deal, but admitted he was still shocked and heart-broken to leave the Roosters, a club he described as his "family" and "brotherhood".

"I wanted to stay, I'd been there nine years, I'd played over 150 games, I've got some long-time friends there and I call them my brothers," Nu'uausala said. "It's like I had to leave my family. It's pretty hard at the moment, I'm still finding my feet, it's a big change in my life.

"I believe in loyalty and honesty, I wanted to be a one-club man for the Roosters because they took me as an 18-year-old kid who was lost and broken and had a lot of issues ... they moulded me into the man I am.

"I thought I'd show some loyalty, but I guess loyalty in our game now doesn't mean [anything]. I had to learn the hard way. But one door closes and a couple more open, Canberra's a good place.

"One day you think you're going to be with your family forever, then the next day it's gone like that. But I'm happy to start something here and create some good bonds with my teammates.

"This is just another challenge. It hurts me, but I'll use that in a positive way. I don't believe in revenge or getting back at people, I'm over that ... I'll use it as positive energy."

It was Raiders coach Ricky Stuart who recruited Nu'uausala to the Roosters as a teenager, in 2005, when the New Zealand Warriors junior was cut by coach Ivan Cleary.

Nu'uausala says his sacking was deserved. He was then part of an Auckland gang, the Samoan Bloods, mixed in street conflict and drugs.

"He [Cleary] told me to move on, I wasn't good enough, but that was on myself," Nu'uausala said.

"That helped me, that was my motivation, when he told me I could never play first grade. That was my own undoing ... I used to be a bit of trouble on the streets.

"We were wannabe gangsters, causing trouble. But all that experience made me who I am.

"It was all about bravado and who's toughest in the street, but as I learned there's always someone tougher than you out there, someone's always got your measure. You think you're the baddest in the hood, but someone's always better."

Nu'uausala has 13 brothers and sisters and sends money monthly to his parents, based in Samoa.

He credits two former teammates as mentors who helped turn his life and career around at the Roosters. One was now-retired Australian backrower Craig Fitzgibbon, another Iosia Soliola, who also joins the Raiders this season from the UK Super League.

Nu'uausala has moved in with Soliola's family, his wife and son, in Canberra.

"I didn't find my feet at Sydney until Fitzy took me under his wing and helped mould me as the player I am. I'm always thankful, I love him like he's my older brother."

"[Soliola] we've known each other since we were kids ... it's good to have him here, that made my decision easier, knowing I could come here and we could play together again."

In a virtual exchange for Nu'uausala, two Raiders players - Matt McIlwrick and Lagi Setu - have gone to the Roosters.

Having played in the Roosters' 2013 grand final win, Nu'uausala said he wants to be part of the rebuild at the Raiders.

"It's been hard to leave what we created [at the Roosters], but I see a real good future, a lot of talented kids and I think they just need a few older heads," the 27-year-old said. "I don't mind a challenge, my whole life's been a challenge, people telling me I can't do this or I can't do that.

"It's a talented group, it's raw, they just need some leadership ... I'm thankful the Raiders opened the door for me."

Nu'uausala can play anywhere in the forwards, from lock to prop, but says he's prepared to play front-row because of a respect for new Raiders teammate Shaun Fensom.

"He's not a big guy, but he's got a big heart and he's earned his right to play that lock role, so I don't mind playing front row."