Players will skip the Australian Open if they are not allowed to practise during their mandatory two-week quarantine due to the risk of injury, Daniel Vallverdu, who has coached some of the biggest names on the ATP Tour, told Reuters.
Tennis Australia (TA) have been in talks with the Victoria state government over the COVID-19 protocols to be established for those arriving ahead of the Grand Slam at Melbourne Park, which is scheduled for January 18 to 31.
State officials have confirmed players will have to undergo quarantine and that the tournament will likely start one or two weeks later than scheduled.
Vallverdu, who currently works with three-time Grand Slam winner Stan Wawrinka, said TA had previously assured players they would be able to practise but nothing had been confirmed.
"Obviously that would be the only way that it would work for the players if they're allowed to practise," the 34-year-old Venezuelan, who has also worked with Grand Slam champions Andy Murray and Juan Martin del Potro, said from Monaco.
"Because they wouldn't be able to just sit in a hotel room for two weeks and then start and play five sets in a Grand Slam. It's just impossible physically, the risk of injury is too high.
"The only way that the players will go to Australia is if they're fully allowed to practise during those two weeks."
Due to border restrictions between states and varied quarantine requirements by local governments, TA also plans to shift all build-up tournaments leading to the Grand Slam to Victoria, which has not reported a locally-acquired case of novel coronavirus infection for over a month.
Organisers of this year's US and French Opens established bio-secure 'bubbles' for players, who were not allowed to leave their hotel rooms except to train and play.
"It's not about the fact whether they can't cope with two weeks of quarantine like many people have done," Vallverdu said by telephone. "I'm sure they can do it, but it's more about the preparation for the Australian Open.
"So close to the event, not being able to practise for 14 days would just be not doable for them."
TA has said it expected to finalise the details "very soon" and that it was in constant touch with the global tennis community over the protocols.
Victoria state sports minister Martin Pakula said the government was confident the Australian Open would go ahead in early 2021.
"Given the health and quarantine protocols that players and support staff will have to adhere to, we understand that Tennis Australia needs to have in-depth discussions with the ATP and WTA, and we support them taking the time to do that thoroughly," Pakula said in a statement on Tuesday.