The ATP tour might be on hold but whenever it's likely to resume, men's tennis could be without their world number one: Novak Djokovic.
On Sunday, in a Facebook live session with a number of Serbian athletes, Djokovic said he was opposed to vaccinations.
The tennis governing bodies have suspended all tournaments until 13 July. But Djokovic says he assumes that a potential COVID-19 vaccine could become a requirement if the season was to resume.
"Personally I am opposed to vaccination and I wouldn't want to be forced by someone to take a vaccine in order to be able to travel," Djokovic said.
"But if it becomes compulsory, what will happen? I will have to make a decision. I have my own thoughts about the matter and whether those thoughts will change at some point, I don't know."
It's fuelled speculation that he might not be competing in a post-COVID-19 shutdown world, if vaccination is required to compete.
"Hypothetically, if the season was to resume in July, August or September, though unlikely, I understand that a vaccine will become a requirement straight after we are out of strict quarantine and there is no vaccine yet."
University of Melbourne's Dr Nancy Baxter was enraged by Djovkic's comments calling for an end to celebrity commentary on the virus.
What began as an online catch up session between countrymen has sparked discussion around the world with tennis fans surprised by Djokovic's stance.
His comments are in contrast to former world number one Ameila Mauresmo, who in late March suggested the idea of essential vaccination if competitive tennis was to resume.
The former coach to Andy Murray said, "I think we're going to have to draw a line under the 2020 tennis season. International circuit = players of all nationalities plus management, spectators and people from the 4 corners of the world who bring these events to life. No vaccine = no tennis."
Djokovic started 2020 with his eighth Australian Open win, and many believed he might be in the running to catch up to Roger Federer and Rafa Nadal's impressive Grand Slam totals. Maybe not anymore.
People in Australia must stay at least 1.5 metres away from others and gatherings are limited to two people unless you are with your family or household.
If you believe you may have contracted the virus, call your doctor (don’t visit) or contact the national Coronavirus Health Information Hotline on 1800 020 080. If you are struggling to breathe or experiencing a medical emergency, call 000.
SBS is committed to informing Australia’s diverse communities about the latest COVID-19 developments. News and information is available in 63 languages at .