The proposed season-opener between Western Sydney Wanderers and Macarthur FC has been moved to December 30, having initially been set to take place on Sunday (December 27).

This decision means that Monday's (December 28) match between Western United and Adelaide United at Kardinia Park in Geelong is now scheduled to open the season.

Western Sydney's home match will face a restricted capacity after a recent cluster of COVID-19 cases in Sydney's Northern Beaches region.

All sporting events in New South Wales - the state Sydney is capital of - have been limited to 50 per cent capacity until at least the end of the month.

The game is due to be Macarthur's A-League debut.

Wanderers and Sydney FC's match in the W-League, the top women's football league in Australia, has been pushed back to December 30 too.

Wanderers and Sydney FC are set to play before the Western Sydney clash with Macarthur in a Bankwest Stadium doubleheader.

"Moving the matches back three days with a reduced capacity supports the Government's risk mitigation plan in relation to crowds and to mobility around the city during this Christmas period and New Year's Eve," said Football Australia head of leagues Greg O'Rourke.

Seventeen of the first 35 matches due to take place this A-League season had to be postponed due to the Northern Beaches outbreak and other anti-coronavirus restrictions in place throughout Australia. 

Perth Glory will not start their season until January 16, following a quarantine period imposed because of their overseas Asian Football Confederation Champions League campaign.

Wellington Phoenix, who usually play in the New Zealand capital, are now based in Wollongong for the season to avoid international travel.

New South Wales today recorded nine new cases from 60,000 coronavirus tests.

That disruption to sporting events is being cause by low case numbers in comparison to other countries should serve as a warning, especially with the Australian Open tennis tournament scheduled to begin in February.