Giannou was due to make his Bulls debut on Wednesday against Glory at Campbelltown Stadium.

But the match has now been postponed after a number of Glory players were struck down by COVID.

All Glory players, coaches and staff with positive results are now in isolation and following the relevant health directives in NSW.

Third-placed Macarthur haven't been in action since losing 3-0 to Sydney on Boxing Day.

The squad was ravaged by COVID-19 after that, with as few as five players spared from contracting the virus.

The late scratching of their game against Glory is a big blow to their hopes of getting back into the groove of regular matches.

It also means they'll face a condensed fixture late in the season.

Macarthur's next scheduled match is on February 6 against Wellington.

Giannou, who hasn't played for the Socceroos since 2019, will be hoping to put in a string of hot displays with Macarthur to boost his international prospects.

The 32-year-old struggled to get on the park for Greek club OFI Crete during the past two years, but his move to the A-League could spark the fresh chapter his career needs.

"Our main thing is that he gets back to enjoying football," Macarthur coach Ante Milicic said.

"He's had a difficult couple of years, he needs those match minutes, he's got quality. He's still got a lot of ambition with his career.

"We won't put a lot of pressure on him, because he has his own high expectations."

Perth Glory have endured a horrid run of forced isolation breaks this season.

The squad was thrown into isolation in mid-December when one of their players tested positive in Queensland.

Glory players had to serve one week of isolation in Brisbane, before being granted special permission to fly back to Perth to spend the second half of their isolation period there.

Perth's 42-day break between games ended when they lost 1-0 to Brisbane on January 19.

Glory posted a 2-1 win over Sydney last Saturday, but they now face another break before playing again.

With no date set for WA's border to reopen, Glory could be forced to spend the bulk of the season on the road.

Australian Associated Press