Rugby Australia yet to sign off on new Super Rugby competition with Moana Pasifika and Fijian Drua

Rugby Australia is hailing the Super Rugby AU season a success and is still working to lock in the competition structure for 2022 with an expanded trans-Tasman format most likely.

Ahead of the grand final between Queensland Reds and the Brumbies in Brisbane on Saturday night, RA boss Andy Marinos says the second year of the domestic competition has been a hit with fans while it's also managed to unearth some new stars.

The decider is expected to draw at least 40,000 fans - close to a capacity crowd at Suncorp Stadium - while the match will be shown on broadcaster Nine's main channel.

"We've been really encouraged - it's been a fantastic competition and it's built and strengthened its narrative as the comp has gone on," Marinos said on Friday.

"To see like the (Western) Force come through and surge and have that upset (over the Reds) in Perth two weeks ago was really good.

"I think what we always wanted was an unpredictability in outcome and to a large degree we've seen that with a number of games going down to the wire.

"There certainly is an optimism. All our metrics are tracking upwards."

Marinos says the popularity of a domestic league has given the RA board "something to ponder", however it's more likely a 12-team trans-Tasman model will be used in 2022.

That includes five teams each from Australia and New Zealand plus new entries Moana Pasifika and Fiji Drua.

He hoped the format would be decided by the end of June.

"There is a lot of value in the trans-Tasman (competition).

"It is good to get a litmus test against your compatriots across the ditch.

"We've just got to wait and see what the whole competition structure is going to look like with the possibility of another two teams joining."

Meanwhile, Marinos was confident the COVID-19 outbreak in Sydney wouldn't impact the inaugural trans-Tasman Super competition which is set to get underway next week.

"We continue as planned - we've got to be able to pivot and be dynamic - I've got a lot of confidence the NSW leaders will get to the bottom of this (virus outbreak) quickly," he said.