Australia's Immigration Minister Alex Hawke said the COVID-19 vaccine mandate applied to all visitors to the nation, with no exception made for players looking to compete at the first tennis Grand Slam of 2022.

The Australian Open is due to start on January 17 in 2022, but latest figures have revealed that more than a third of players on the men's and women's tour are not double jabbed.

The Association of Tennis Professionals told Australian newspaper The Age that just 35 per cent of players were fully vaccinated, while the Women's Tennis Association revealed the figure stood at 40 per cent as of the start of last week.

"The Government in establishing its borders has said that you'll need to be double vaccinated to visit Australia," Hawke told ABC Radio.

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

"I mean that every visitor to Australia will need to be double vaccinated."

The move casts further doubt over the participation of men's world number one Novak Djokovic.

The 34-year-old Serbian, who is seeking a record 21st Grand Slam title and 10th Australian Open crown, is opposed to mandatory COVID-19 vaccines and refuses to reveal his inoculation status.

"I don't have a message to Novak," said Hawke.

"I have a message to everybody that wishes to visit Australia.

"He'll need to be double vaccinated."

Health Minister Greg Hunt added: "They [the rules] apply to everyone without fear or favour.

"It doesn't matter whether you are number one in the world or you are anything else."

Djokovic is looking to hold the standalone all-time record for the most men's singles Grand Slam titles as he is currently tied with Switzerland's Roger Federer and Spain's Rafael Nadal on 20.

But speaking to Serbian newspaper Blic earlier this week, Djokovic said he was unsure whether he will defend his men's singles title in Australia.

"Things beings as they are, I still don't know if I will go to Melbourne," he said.

"I will not reveal my status, whether I have been vaccinated or not.

"It is a private matter and an inappropriate inquiry.

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

"Whatever you say, 'yes', 'no', 'maybe', 'I am thinking about it', they will take advantage."

Australian Senator Matt Canavan argued that the fact Djokovic had previously contracted coronavirus should be enough to compete at the tournament.

But Victorian Australian Medical Association President Dr Roderick McRae was opposed to Canavan’s comments.

"I understand he [Djokovic] had it [coronavirus] but, believe it or not, the immunity from the vaccination is better than the immunity from catching the disease," said Dr McRae.

"I think there is an element of standards [here]. 

"It's important our leaders make these decisions in our interests and it [banning unvaccinated travellers] demonstrates to the community just how important we take this."

Greece's world number three Stefanos Tsitsipas revealed in August that he would only get vaccinated for COVID-19 if it became mandatory to compete in tennis.

He later said he planned to get inoculated this year after being criticised by the Greek Government over his reluctance.

Russia's Andrey Rublev has also previously expressed concerns over the COVID-19 vaccine but has now revealed that he hopes to get vaccinated in time for the Australian Open.

Austria's 2020 US Open champion Dominic Thiem said he was awaiting for the availability of the Novavax vaccine, which is currently undergoing trials, before being inoculated.

"I actually wanted to get vaccinated with the inactivated Novavax vaccine," said Thiem.

"If that doesn't work, I'll just take another vaccine."

This year’s Australian Open was postponed by three weeks with players having to undergo a 14-day hotel quarantine period upon arrival.

It was also partly staged behind closed doors due to a state-wide lockdown being imposed in Victoria.

Next year's Australian Open is scheduled to be held from January 17 to 30.