Tupouniua goes from grandstand to thick of the action

Just eight months ago Sitili Tupouniua stood in the Mt Smart Stadium stands as a member of Tonga's 'sea of red', singing an en masse rendition of the Australian national anthem that stunned the biggest names in rugby league.

On Saturday the Roosters' rookie will join Mate Ma'a Tonga on centre stage, making his international debut against his native New Zealand and capping a whirlwind rise in 2019.

Tupouniua will come off the bench for Kristian Woolfe's side against the Kiwis, who he represented at under 20s level as an Auckland-born and raised product before shifting to Bondi at age 17.

His parents' full-blooded Tongan heritage sees Tupouniua bolster one of rugby league's most formidable forward packs after just eight first grade games.

And last October Tupouniua joined a 26,214-strong crowd made up almost entirely of Tongan supporters, who sung a spine-tingling 'Advance Australia Fair' in a mark of respect to the Kangaroos' opposition, who then prevailed in a bruising 34-16 affair.

"It's a massive honour, I've always been proud of my Tongan heritage and to get named ... I've been dreaming of it the last few games," Tupouniua told NRL.com.

"Their last game I was actually in the stands, in the crowd watching against Australia. Being in that crowd and listening to it, you couldn't hear yourself think.

"But I did imagine running out in front of it and getting that opportunity.

"I didn't expect it to come this quick but if I get the chance to do it, it would be something I'd never forget."

Tupouniua says he had no contact from the Kiwis in the lead-up to being selected for Tonga, and will soak up his first international experience rather than dwell on any long-term commitment to either nation.

His rapid rise to prominence was rewarded further with a two-year Roosters extension last month, which came in the face of serious interest from NRL rivals including the Warriors.

Having overcome two shoulder reconstructions to claim a regular spot on Trent Robinson's bench this year, Tupouniua has been sounding out fellow Tongans Siosiua Taukeiaho and Daniel Tupou about one of rugby league's most enthralling spectacles.

"I've talked to Siua and Toops about these Tonga games," Tupouniua said.

"They reckon it's unlike any other game, it's different to a grand final, a different atmosphere.

"The game, the crowd and the boys that you're playing with, representing Tonga, they reckon it's unreal. I'm keen to get out there.

"When I got the call, I actually missed Kristian's call because I was training but he flicked me a text afterwards and when I read that I was just buzzing.

"Mum and dad, they were shocked when I told them. It's quicker than anyone expected but they were happy as, my whole family's been messaging me ever since and they'll be out there for the game too."