Novak Djokovic has been "playing by his own rules" and has put his bid for a record 21st grand slam title at risk by not following Australia's COVID-19 vaccination requirements, according to Greek world number four Stefanos Tsitsipas.

Djokovic was included in the Australian Open draw on Thursday, though uncertainty hangs over his participation, with Immigration Minister Alex Hawke yet to announce whether he will use his power to cancel Djokovic's visa. 

The 34-year-old, a vaccine sceptic, fuelled widespread anger in Australia when he announced he was heading to Melbourne with a medical exemption from requirements for visitors to be fully vaccinated against COVID-19.

The Australian Border Force said his exemption was invalid and he was held at an immigration detention hotel, but a court later allowed him to stay on grounds that officials had been "unreasonable" at his interview in a seven-hour process.

Tsitsipas, who himself had been hesitant about getting the COVID vaccine in 2021, got vaccinated and criticised Djokovic for the actions he has taken in an interview with India's WION news channel.

"No-one really thought they could come to Australia unvaccinated and not having to follow the protocols … it takes a lot of daring to do and putting the grand slam at risk, which I don't think many players would do."

The ATP, which governs men's tennis, earlier said 97 of the top 100 male players were vaccinated.

American world number 93 Tennys Sandgren told reporters earlier this month that he had pulled out of the Australian Open due to the vaccine mandate and he opted not to apply for a medical exemption.

Asked if Djokovic should defend his title at Melbourne Park, Tsitsipas said: "There are two ways to look at it. One side of it is that almost every single player is fully vaccinated … and have followed the protocols to play in Australia."

“I chose to go and be 100 per cent ready for whatever was to come and not having to think about anything else.

“For me, it worked one way, for Novak, it worked another way. That doesn’t really mean that my way is the right one and his way is the wrong one, it’s just each person's perception about it.”

However, Tsitsipas did question why some players, including Djokovic, were allowed to not get vaccinated and still make it to Australia.

“The stats say 98 per cent of players have been vaccinated and did what they had to do in order to come and perform and play in Australia,” Tsitsipas said.

“[But] not everyone is playing by the rules of how Tennis Australia and the government have been putting things.

ABC/Reuters