Djokovic has repeatedly refused to reveal whether he has received a jab, having also previously expressed hope the vaccine would not become mandatory for players on the ATP circuit.

Questions about the defending champion's return to Melbourne Park, where he would be hunting a staggering 10th Australian Open title, were raised when Victoria recently introduced a vaccination mandate for professional athletes.

Premier Daniel Andrews said on Tuesday that unvaccinated sports stars would be unlikely to receive a visa, making the domestic restriction a moot point.

And on Wednesday, Immigration Minister Alex Hawke confirmed there was no prospect of travel rules being relaxed for incoming tennis players.

"Not at this time. Our health advice is that when we open the borders, everyone that comes to Australia will have to be double vaccinated," Mr Hawke told ABC Radio.

"I don't have a message to Novak.

"I have a message to everyone who wishes to visit Australia, you'll need to be double vaccinated.

"That's a universal application, not just to tennis players."

Djokovic, who is tied with Roger Federer and Rafael Nadal on a record 20 grand slam titles, said on Monday he was unsure whether he would be playing at Melbourne Park.

"I will not reveal my status, whether I have been vaccinated or not. It is a private matter and an inappropriate inquiry," Djokovic told the online edition of Serbian daily Blic.

"People go too far these days in taking the liberty to ask questions and judge a person.

"Of course I want to go, Australia is my most successful grand slam tournament.

"I am following the situation regarding the Australian Open and I understand the final decision (on COVID-19 related restrictions) will be made in two weeks.

"I believe there will be a lot of restrictions just like this year, but I doubt there will be too many changes."

Australian Associated Press