League central has already begun selling tickets to the final-four clash at Moore Park, where the Sydney Roosters will meet either South Sydney or St George Illawarra.

Greenberg confirmed that, under the NRL finals policy, the location of the grand final qualifier is at the behest of the governing body and that they wanted to reward the minor premiers.

"The discretion is for us to play it at the right stadium. We think we're playing in the right stadium," Greenberg told AAP.

"If we put a house full sign up, that's a good thing for the game.

"We think, in a forecast number, that looks maybe somewhere between 40,000-50,000 crowd.

"And that's why we're playing at Allianz."

The decision could be considered in contrast to their policy for week one of the finals, where suburban grounds are snubbed in favour of major venues in the host city.

The annual Anzac Day clash between the Roosters and Dragons has attracted in excess of 34,000 people each year since 2011, and hit a record 41,152 figure in 2018.

The Roosters met the Rabbitohs in a preliminary final at ANZ Stadium at Homebush just four years ago, which drew a crowd of 52,592.

They also had 59,708 people at the final regular season game the previous year that decided the minor premiership.

The capacity at Allianz Stadium is 45,500 and Greenberg believes the NRL would be criticised no matter which way they went.

"If we get 45,000 and we play it at ANZ, I know there'll be criticism: 'Why aren't we playing it at Allianz?' If there's 55,000, there'll be criticism saying, 'You could've got more'," Greenberg said.

"The reality is we have to make a decision now because it's two weeks away.

"People can judge us afterwards. We've already got the game on sale."

Greenberg said the NRL hadn't given up hope of opening next season in the United States but were already looking at alternative venues to launch round one.

"We need it to be commercially attractive for us to do that, so that means securing funding, whether it's through tourism or travel partners," he said.

"That's been problematic, it's been difficult for us to do. We're still working on it.

"If it doesn't happen this year, we're continue planning it for future years."

Australian Associated Press