Perth's Optus Stadium will be able to host up to 30,000 fans as early as this weekend, and 60,000 fans in less than a month, as WA enters phase four of easing coronavirus restrictions.

It means that Fremantle and West Coast should be able to play in front of 30,000 fans as early as Round 6, after their four-week stay at the Gold Coast hub finishes.

If all goes to plan, crowds will double to Optus Stadium's full capacity in less than a month, with phase five of WA Premier Mark McGowan's plan to be rolled out on Satuday July 18.

โ€œPhase four is another giant step for our state,โ€ McGowan announced today.

โ€œFrom Saturday, our major sport and entertainment venues will be able to operate at a 50 per cent capacity rule. That means Optus Stadium, HBF Park and RAC Arena will be able to hold events with up to 50 per cent capacity crowds,โ€ he said.

"Big events at these venues can be organised over the next few weeks. Western Australians will hold the largest crowds in the country by far.

โ€œPhase five is planned to be introduced on Saturday July 18, which is three weeks after phase four. As we have done previously, we will carefully monitor the introduction of phase four and its impact on our community before we move to the next phase."

But it is still unclear whether sides, especially from Victoria, will be able to travel to Western Australia in the near future. The state's border remains closed.

โ€œI wonโ€™t be pressured into making a rushed decision on our hard border,โ€ McGowan said.