Play at Australian Open warm-up tournaments in Melbourne has been cancelled for Thursday after a Coronavirus scare, organisers announced.

There will be no matches at any of the six ATP and WTA Tournaments after up to 600 players and officials were told Wednesday to isolate and get tested because a worker at a hotel tested positive for COVID-19.

“There will be no matches at Melbourne Park on Thursday. An update on the schedule for Friday will be announced later today,” the Australian Open’s official Twitter feed announced.

“Health Authorities have advised us that a hotel quarantine worker has tested positive for COVID-19,” AO added.

“Those associated with the AO who quarantined at the hotel now need to be tested and isolate until they receive a negative test result.”

Organisers said they would work to “facilitate testing” as quickly as possible.

Daniel Andrews, premier of Victoria State, said the man infected last worked at the Grand Hyatt Hotel in Melbourne on Jan. 29 and anyone there was considered a casual contact.

The Grand Hyatt was one of the designated hotels used to accommodate part of the contingent of more than 1,000 players, coaches and officials which had jetted into largely virus-free Australia last month for 14 days’ lockdown ahead of the opening Grand Slam of the year which begins Monday.