MELBOURNE -- All competition at six Australian Open tuneup events scheduled for Thursday was called off after a person working at one of the tournaments' Melbourne quarantine hotels tested positive for COVID-19.
Players preparing for the year's first Grand Slam tournament, which is supposed to begin Monday, must isolate at their hotels until they test negative for the illness caused by the coronavirus.
"We will work with everyone involved to facilitate testing as quickly as possible," Tennis Australia said in a statement announcing the postponement of all matches that were to be played Thursday at Melbourne Park.
Victoria's state premier, Daniel Andrews, said he called a late-night news conference Wednesday to announce the case "through an abundance of caution," although he did acknowledge that new restrictions could impact hundreds of people associated with the Australian Open.
Andrews spoke before all of Thursday's play was postponed, which he acknowledged was a possibility. But as for the Australian Open, Andrews said: "At this stage, no impact on the tournament proper."
Any players, coaches or officials who quarantined at the Grand Hyatt hotel in Melbourne were deemed to be casual contacts of the 26-year-old infected man and are required to remain in their hotels until they test negative.
Everyone in the city will be required to wear masks while indoors.
The hotel advertises it has 550 rooms, including 25 premium suites, so potentially hundreds of people associated with the tournament could be forced back into isolation. That could test the resolve of players who have recently come out of two weeks in quarantine and could give ammunition to critics of the decision to allow people to fly in from all over the world for the year's first major.
Australian Open organizers didn't immediately have details of how many players would have to isolate.
Under the current plans, up to 30,000 spectators are expected daily at Melbourne Park for the two-week Grand Slam event, and there was no immediate indication of a change.
Everyone who arrives in Australia must undergo a mandatory 14-day quarantine under the COVID-19 pandemic regulations. The Australian Open used three hotels in Melbourne for the bulk of the players to quarantine and had other secure accommodation and facilities in Adelaide, South Australia, for some of the biggest stars, including Serena Williams, Naomi Osaka, Novak Djokovic and Rafael Nadal.
Players were tested every day during quarantine and weren't allowed to leave their hotels without a negative result.
The infected worker tested negative on his last day at the hotel on Jan. 29, but subsequently tested positive and has been working with government and health officials on contact tracing. Andrews said that the man was in a medical facility and that dozens of his close contacts were in mandatory isolation.
"This is one case. There's no need for people to panic," Andrews said. "There's no need for people to be alarmed. We Victorians know what to do, and we have proven, as a state, very successful at managing these sorts of outbreaks, these sorts of issues."
Earlier Wednesday, Victoria health officials had announced that the state had gone 28 days without a case involving local transmission.
Australia has 909 deaths attributed to COVID-19, including 820 in Victoria state. Most of those were during a second deadly wave last year in which a hard lockdown and overnight curfews were put in place in Melbourne.