But there is confidence it can be done, and that it would create a similar - if not quite as big - buzz as the Nines. There's optimism the concept would also draw visitors across the Tasman.
Along with the Warriors, the proposed double-header could involve some of the bigger clubs in the NRL, who have traditionally strong fan bases in New Zealand.
That would mean the likes of the Broncos, Roosters, Raiders, Bulldogs and Dragons being near the top of the list. The Sea Eagles and Storm are also possibilities, though they have already committed to another Suncorp double-header in 2018.
The Herald on Sunday understands planning and negotiations with the NRL are well advanced.
Crucially, the proposal also has the support of Auckland Council's events arm Ateed, who are believed to be committed to finding an alternative to the Nines, should it not go ahead in Auckland in 2018.
There are two main issues.
The NRL would prefer to test a new market with the Nines, with Perth seemingly the favourite as their state government is willing to invest heavily and they have a new 60,000-capacity stadium to fill.
The other factor, specific to 2018, is a concern over player workload, given the World Cup at the end of this season. Due to changes to the international eligibility rules, more NRL players will be involved in the tournament, which runs for more than five weeks from October 27.
The NRL All-Star game has already been shelved for the 2018 season due to player welfare factors.