A player from A-League side Newcastle Jets on Saturday became Australia's first professional footballer to test positive for coronavirus.
The man was not named but reports said he was involved in the team's Monday night 2-1 home win over Melbourne City behind closed doors - the last game before the season was suspended due to the pandemic.
A member of staff at Wellington Phoenix was also confirmed as having COVID-19.
"Newcastle Jets can confirm that a player in its A-League squad has returned a positive test," the club said in a statement.
"The player and his family are in good health, and currently in quarantine in accordance with New South Wales Health protocols."
It added that the squad were monitoring their health and anyone showing symptoms would self-isolate.
New Zealand-based Phoenix said a football operations employee had also tested positive and "all players and staff who had direct contact with the staff member are being monitored for possible signs of infection".
The A-League was one of the last football competitions in the world still running until the plug was finally pulled on the 11-team domestic league this week.
The positive tests came as Australia's footballers' union threatened legal action against Perth Glory after players were stood down without pay.
Most clubs appear to be waiting until Football Federation Australia reviews the league suspension on April 22 before deciding what steps to take to weather the financial fallout.
But with no revenue from ticket sales, Perth Glory owner Tony Sage made the "heartbreaking" decision to stand down the squad, effectively keeping them on the books but without salaries.
"I can't remember sadder days except when my mum died and my brother died. It's heartbreaking. Very, very sad," he told the West Australian newspaper, adding that he expected other clubs to follow suit.
Professional Footballers Australia (PFA) was not impressed, demanding their immediate reinstatement and threatening legal action under the country's Fair Work Act if the club does not comply.
"The players acknowledge that everybody in Australia is facing a collective challenge as a result of the COVID-19 pandemic," PFA chief John Didulica said in a statement.
"The PFA continues to call for a collective solution to address our game's challenges, as has been the approach adopted by... sporting bodies around the world.
"However, Tony has shown his preference for unilateral, reckless and unlawful action."
Didulica warned other clubs considering similar moves would also face legal action.
Football is not alone in working through harsh financial consequences brought by the pandemic, which has shut down sports events worldwide.
The Australian Football League, the nation's most popular spectator sport, struck a deal with its players' union on Friday to slash wages by up to 70 percent to ensure the game can survive.
Rugby league and rugby union are both locked in similar crisis talks.