Watch: No play, but plenty of tests for players at Australian Open

All competition at six tournaments scheduled for Thursday was called off overnight and 520 people who flew to Melbourne for the Australian Open were ordered to isolate in their accommodation and get tested after a man who worked at one of the quarantine hotels until last Friday tested positive for the coronavirus.

Melbourne: Players were isolating and getting tested for COVID-19 instead of playing tune-up tournaments four days before the Australian Open as concern grew over the impact on the year's first tennis major.

All competition at six tournaments scheduled for Thursday was called off overnight and 520 people who flew to Melbourne for the Australian Open were ordered to isolate in their accommodation and get tested after a man who worked at one of the quarantine hotels until last Friday tested positive for the coronavirus.

The Australian Open is scheduled to begin Monday, and preparations have already been disruptive and chaotic.

All players and their entourages and everyone else flew into Australia for the tournament had to spend 14 days in hotel quarantine. Of those, 72 players were forced into hard lockdown after passengers on their charter flights later returned positive tests for the virus.

Anyone connected with the tournament and who quarantined at the Grand Hyatt hotel in Melbourne were deemed to be casual contacts of the 26-year-old infected man and were undergoing testing at a dedicated facility.

Allen Cheng, Victoria state's deputy chief health officer, said authorities were being extra cautious.

"We think the risk to other guests at the hotel, so tennis players and their accompanying staff, is relatively low because they were in the rooms at the time as opposed to staff who were outside the rooms," Cheng told a news conference Thursday.

"So we're testing them to be sure, and it's precautionary."

Cheng said six people in the Grand Hyatt during the quarantine period for the Australian Open had tested positive and were transferred to a medical facility, and it was likely the man a resident support officer was infected there.

"We are aware that he was on a floor where there were cases," Cheng said.

Cheng said it was "unlikely" the Open will be canceled.

Victoria State Premier Daniel Andrews said in news conference late Wednesday that he didn't expect the Feb. 8-21 Australian Open to impact, although he has added that it's an unfolding situation.

He said the late-night announcement of the positive case was done through an abundance of caution.

Andrews on Thursday confirmed close family contacts of the infected worker had tested negative for COVID-19 and contact tracing was advanced.

Everyone in the city will be required to wear masks while indoors.

The latest coronavirus restrictions could test the resolve of players who have recently come out of two weeks in quarantine.

It will also give ammunition to critics of the government decision to allow people to fly in from all over the world at a time when coronavirus cases were surging in some countries but under control in Australia.

Australian Open organizers didn't immediately have details of how many players were ordered 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.

All arrivals in Australia must undergo a mandatory 14-day quarantine under the COVID-19 pandemic regulations.

The Australian Open chartered 17 flights and used three hotels in Melbourne for the bulk of the players to quarantine and had other secure accommodation and facilities in Adelaide, South Australia state, for some of the biggest stars, including Serena Williams, Naomi Osaka, Novak Djokovic and Rafael Nadal.

Players were tested every day during quarantine and all were cleared before the tuneup tournaments began at Melbourne Park on Monday. The first three days of competition were incident free.

"This is one case. There's no need for people to panic," Andrews said in his news conference announcing the case and a raft of low-key restrictions.

"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."

Australia has 909 deaths attributed to COVID-19, including 820 in Victoria state. Most of those were during a second deadly wave last year when a hard lockdown and overnight curfews were put in place in Melbourne.