Novak Djokovic continues to stay at the Melbourne Park hotel, which is used to house immigration detainees after the Serbian tennis player had his visa to enter Australia cancelled by the country's Border Force (ABF) for not meeting entry requirements.

The men's singles world number one had revealed that he was awarded a medical exemption to compete at the Australian Open after his decision not to reveal his vaccination status. However, when Djokovic arrived in Australia, he was denied entry, and is now facing deportation from the country.

Boris Becker, who was the Serb's coach between 2013 and 2016, believes his former charge is making a big mistake by not taking the vaccination. The German feels that apart from threatening his immediate participation at the Australian Open, he is in danger of denying himself the chance to cement his legacy as the greatest ever.

The 34-year-old has won the Australian Open on nine previous occasions and would have been the favourite going into the tournament. Djokovic would have had the chance to overtake Roger Federer and Rafael Nadal with whom he is currently tied at 20 men's singles Grand Slam titles each.

"As his former coach I am so close to Novak Djokovic that I would almost regard him as family — but like in all families you sometimes have disagreements," Becker wrote for the Daily Mail.

Novak Djokovic
Chairman of the board! Novak Djokovic holds the winner's trophy in front of the honours board and points to his name AELTC/Thomas Lovelock/POOL

"And on this occasion I think he is making a big mistake in not getting vaccinated. It is one that threatens what remains of his career and his chance to cement himself as the greatest player of all time."

Becker has urged Djokovic to get jabbed as soon as possible, but admits that it is unlikely the Serb will heed his advise, as he is very stubborn and stays true to his beliefs. He also feels the younger generation is more averse to taking the vaccine as they see themselves as invincible.

However, he feels Djokovic's decision not to take the vaccination could hamper him not only in Australia but in other parts of the world when he travels for tournaments. The Covid-19 pandemic is on the surge yet again with a number of countries reporting a high number of cases.

"I did not have the chance to speak to Novak but I would urge him to get vaccinated — although whether he would listen is another matter," Becker added.

"He is incredibly strong-willed, with very firm beliefs. If he does not, then in 10 years he will look back on it and realise he made a mistake. It is not just about Australia. The fact is that we are living in a different world and he is going to find it very hard to live the life of a professional tennis player travelling around without the vaccination."

Djokovic's case will be again heard by the court on Monday, when it will be decided if the world number one will be able to stay in Australia and compete in the 2022 season's first major. There has been a tremendous outpouring of support for the Serbian star with candlelight vigils taking place outside his hotel.

Rafael Nadal and Novak Djokovic
Rafael Nadal, Roger Federer and Novak Djokovic are on collision course in the French Open Thomas SAMSON/AFP