Novak Djokovic’s visa row with the Australian authorities could easily have been avoided if he had been vaccinated, his great rival Rafael Nadal has said.

The Serbian is being detained at a quarantine hotel in Melbourne that has housed asylum seekers ahead of an appeal hearing on Monday after he challenged the decision of the Australian Border Force (ABF) to cancel his visa and deport him.

The 34-year-old had travelled Down Under after announcing he had received a medical exemption from Covid-19 vaccination rules to compete in the Australian Open, which starts on January 17.

However, the ABF said Djokovic “failed to provide appropriate evidence to meet the entry requirements to Australia” and cancelled his visa.

Nadal, who like Djokovic has won 20 grand slam titles, had limited sympathy for the Serbian, and said: “I have been vaccinated twice. If you do this, you don’t have any problem to play here.

“The only clear thing is if you are vaccinated, you can play in the Australian Open and everywhere, and the world in my opinion has been suffering enough to not follow the rules.

“There are rules, and if you don’t want to get the vaccine, then you can have some troubles. I think if he wanted, he would be playing here in Australia without a problem.

“He made his own decisions, and everybody is free to take their own decisions, but then there are some consequences.

“Of course I don’t like the situation that is happening. In some way I feel sorry for him. But at the same time, he knew the conditions months ago, so he makes his own decision.”

Australian Prime Minister Scott Morrison thanked ABF officers “for doing their job implementing the Government’s policies” and noted entry to Australia “requires double vaccination, or a medical exemption”.

“I am advised that such an exemption was not in place, and as a result he is subject to the same rule as anyone else,” Morrison added.

The nine-time Australian Open champion has been granted a temporary reprieve of sorts after the Federal Court of Australia adjourned his appeal until Monday and granted him the right to remain in the country at least until the appeal is heard.

Djokovic is being detained at the Park Hotel in the Carlton suburb of Melbourne. Past detainees have reported receiving food containing maggots and mould, with one asylum seeker telling SBS News: “Even an animal cannot eat this type of food.”

Protesters supporting Djokovic gathered outside the hotel.

Djokovic has not said why tournament organisers granted him a medical exemption. Officials had insisted all players must be vaccinated to travel and compete.

It has been reported Djokovic had not applied for a visa that allows exemptions for unvaccinated people. Djokovic has not publicised whether or not he has been vaccinated, but has previously said he is opposed to vaccination.

News of the tournament exemption provoked a huge public and political backlash in a country with some of the tightest Covid-19 restrictions in the world.

Shortly before the ABF statement, Serbia’s president Aleksandar Vucic weighed into the debate and criticised the way Djokovic had been treated.

Vucic wrote on Instagram: “I just finished a phone conversation with Novak Djokovic.

“I told our Novak that the whole of Serbia is with him, and that our authorities are taking all measures to stop the harassment of the best tennis player in the world in the shortest possible period.

“In accordance with all norms of international public law, Serbia will fight for Novak Djokovic, for justice and truth.”