The New Year's Eve Big Bash League match will proceed as planned in Adelaide tonight, despite four players from the Sydney side testing positive to COVID-19.

The match was in doubt after four members of the Sydney Thunder squad tested positive and were put in isolation.

Those tests were carried out after someone in the camp returned a positive Rapid Antigen Test.

The remainder of the squad have returned negative PCR tests and can play.

Cricket Australia's general manager Alistair Dobson said the clubs and SA Health have worked together to ensure "additional safeguards are in place".

"We thank the Strikers, Thunder and SA Health for their hard work today to ensure this match can proceed," he said.

Last night's match between the Melbourne Stars and the Perth Scorchers was postponed after the Stars recorded a positive case.

That club has since confirmed seven players and eight staff have tested positive.

General Manager Blair Crouch said the club is working with Cricket Australia on its immediate fixture and will provide an update as soon as possible.

"First and foremost, we wish everyone affected by this outbreak a quick and speedy recovery," he said in a statement.

"The health and safety of our players and staff will continue to be our priority, especially with the challenges the new Omicron variant presents."

The Sydney Ashes Test has also been thrown a curve ball, with batter Travis Head testing positive to the virus.

He will be unavailable for selection for the fourth Ashes Test, starting in Sydney on January 5.