Dallin Watene-Zelezniak expects his family to be divided when Tonga meet New Zealand in Saturday's World Cup semi-final.
"My family is going to be split down the middle on the weekend," Watene-Zelezniak said.
"It's going to be a win-win for my family, no matter who wins the game."
A Tonga victory in Newcastle would rank among the island nation's greatest sporting achievements; it has never reached a World Cup final in any sport.
Watene-Zelezniak, 31, has played 13 times for New Zealand and captained the Kiwis on five occasions.
Born in Hamilton, he grew up admiring his great-grandfather Steve Watene, the first Māori man to lead the Kiwis and the only former NRL player to serve in New Zealand's parliament.
"My great-grandfather got to captain the Kiwis as well, so that was pretty special to be able to put his name back where it once was," he said.
He said representing New Zealand and Tonga had both been ambitions, honouring his grandmother and father, and added: "I've been able play for both countries now, so I feel quite blessed."
The Warriors winger said he switched allegiance now because he wanted to contribute while still at his best.
"I didn't want to go to Tonga when I was old and couldn't really do anything," he said. "I actually wanted to come to Tonga to make an impact."
In 2019, he captained New Zealand in a defeat to Tonga, only the Polynesian side's second win over the Kiwis.