WESTERN Australian Premier Mark McGowan has announced his state won't move into phase five COVID-19 restrictions until at least October 24, meaning Optus Stadium will be at half-capacity through that date.

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The AFL Grand Final is set to be played on October 17 or 24 – depending on if there is a bye between round 18 and the first week of finals – so the Perth venue may be able to host only 30,000 fans.

The Gabba in Brisbane remains in pole position to hold this year's decider, although it's likely that ground may have fewer than 20,000 if it's awarded the AFL's pinnacle match.

The Gabba ready to host Richmond and Gold Coast. Picture: AFL Photos

Lions chairman Andrew Wellington told SEN last week he expected by mid-October the Gabba would be in a better position than it is currently, but that he was "not sure" a packed 37,000-strong capacity was realistic.

Meanwhile, the Tasmanian government has postponed its borders opening until at least December 1, so neither Hawthorn nor North Melbourne will host games there this season. 

Hawks chief executive Justin Reeves said they were understanding of Tasmanian Premier Peter Gutwein's decision.

"We will always operate in the best interests of the Tasmanian people, and on this occasion that unfortunately means not travelling to our home away from home in 2020," Reeves said. 

The University of Tasmania Stadium in Launceston. Picture: AFL Photos

"While we are incredibly disappointed, we also fully support the Premier's decision.

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"We look forward to continuing our long-standing partnership and playing games in Tassie in 2021 and beyond."

Both Hawthorn and the Kangaroos were originally slated to play in Tasmania four times this year, including a match against one another at Launceston's University of Tasmania Stadium.