MELBOURNE -- Dozens of tennis stars stuck in hotel quarantine ahead of the Australian Open were told Monday they would get no "special treatment" to leave their rooms to train, despite complaints from some players.

Australian health authorities rejected demands for tough isolation rules to be eased, as players resorted to hitting balls off windows, walls and upturned beds in the hope of being ready for the year's first Grand Slam.

The Australian Open is due to make a delayed start in Melbourne on February 8, but its troubled build-up hit further problems after positive coronavirus cases were detected on three of the 17 charter flights that carried players and staff.

The 72 players on the three planes have been deemed close contacts of the four COVID-19 cases and barred from leaving their hotel rooms for 14 days, as largely virus-free Australia tries to prevent community transmission.

Health authorities said they discovered two more cases linked to the tournament on Monday, bringing the total for the Australian Open cluster to six.

Several players have taken to social media to complain about conditions.

World number one Novak Djokovic -- who arrived on a virus-free flight and is being allowed to train in a bio-secure bubble -- reportedly sent a list of demands to tournament organizers that included allowing players to move to private homes with tennis courts.

Victoria Premier Daniel Andrews smashed back that request, saying authorities would not bend strict health rules any further for the players.

"There's no special treatment here. Because the virus doesn't treat you specially, so neither do we," he said.

The arrangements have sparked a backlash in Australia, with some social media users questioning why more than 1,000 players and staff were flown in for the sporting event, when tens of thousands of Australians remain stranded overseas.

The country closed its international border in March and has since limited the number of its own citizens who can return each week.

Meanwhile the majority of players are allowed out to train for five hours a day, unlike other returned travellers who are confined to their hotel rooms for the full 14 days.

Andrews said all players knew about Australia's strict quarantine rules ahead of their flights.

"The notion that there's been any change, the notion that people weren't briefed, I think that argument really has no integrity whatsoever," he said.

Some pointed out that the host city of Melbourne had endured a gruelling four-month lockdown last year after a virus outbreak.

"Our health safety is more important to us than your feelings of privilege and entitlement," one Twitter user wrote.

"Most of us here in Melbourne do not want tennis players here potentially reintroducing the virus and causing us to go back to harsh restrictions," another added.

French player Alize Cornet issued an apology to Australians on Twitter after earlier deleting a tweet that called the quarantine "insane".

"Your reaction to this tactless comment made me realize what you've been through last year & how much you suffered," she wrote.

"I guess I feel a bit anxious about all this & I better have shut my mouth."

Staff are dressed in protective gear at a Melbourne hotel housing tennis players

Tennis Australia has begun delivering exercise equipment to the isolated players who are concerned about the risk of injury when they finally hit the courts for a week of lead-in tournaments to start in Melbourne from January 31.

New Zealand player Artem Sitak said he could hear tennis balls hitting the walls "everywhere" in his hotel as players embraced "creative" forms of exercise.

The doubles player told public broadcaster ABC the situation was "not ideal" but he was "staying positive and hoping for the best".

"I'm trying to do as much as I can -- all the stretching, all the exercising and anything I can possibly do -- and hoping for the physios when they come out to do some magic here," he said.