Cronulla prop Fifita suggested his cousin was considering committing to the Mate Ma'a for next month's test against New Zealand in what would be a massive blow for Queensland's depth.
David Fifita was thought to be a leading contender to grab a Queensland bench spot for Origin I in a fortnight.
But Andrew Fifita said he was one of a host of young players with dual eligibility who wanted to commit to the fast-emerging Pacific nation.
"I feel like change is coming, especially for the international game," Andrew Fifita said.
"When I first started (and pledged allegiance to Tonga) at the World Cup, my name went through hell. Six weeks after that when the World Cup was finishing, it was the best thing that happened to the international game.
"I see young kids coming through and I can speak highly of my little cousin, little Dave, how he has pretty much changed his personality and he wants to play for Tonga. He wants to excel that way."
Pressed further on whether David, 19, had made a decision, Andrew said: "I don't know whether (Queensland) will throw him in such a big arena.
"I'm not too sure. He's family and whatever he chooses I will be 100 per cent behind him."
David Fifita is dual eligible for both Queensland and Tonga, the NRL confirmed.
Maroons coach Kevin Walters will on Monday name his side for Origin I and David Fifita cannot turn out for both, given Tonga play the Kiwis in Auckland on June 22, the day before Origin II.
QRL officials on Wednesday expressed surprise when told it had been suggested that David Fifita was considering representing Tonga.
He had been a fixture of the Queensland junior pathways system, playing for the Maroons at under-15s, under-18s and under-20s as well as taking part in their Emerging Maroons camp earlier this year.
Pangai Jr was in the running for a NSW call-up this series, after late last year taking part in a Blues camp overseen by Brad Fittler.
But after representing Tonga in four test matches over the last two years, he elected to stick with the Mate Ma'a.
"(Pangai) ran it past me and I always said (Origin) is something you have to experience," Andrew Fifita said.
"I'm not too sure what changed his mind. I always said give it a crack, the atmosphere ... you'll thrive off it and love it.
"But now we (Tonga) are pulling crowds as big as Origin. It's very loud and important for our people. Change is coming."