Count Greek tennis star Stefanos Tsitsipas – ranked third in the world – among his country's rabid anti-vaxxers whose refusal to be vaccinated against COVID-19 has slowed the fight against the pandemic.

As Prime Minister Kyriakos Mitsotakis has pleaded with people to be vaccinated and made it mandatory for health care workers alone so far, Tsitsipas said he won't get the shots – unless tennis' professional association ATP requires it.

He hasn't said why he refuses to be vaccinated although anti-vaxxers generally don't believe it's safe or effective or is an international conspiracy to alter their DNA and control their minds.

But even if it's principle, he's willing to bend it to compete and make money on the tour where he has rocketed to near the top of the rankings it unable to beat his top rivals yet.

“No one has told me anything. No one has made it a mandatory thing to be vaccinated,” he told reporters, when asked if he would seek a vaccine while competing in the US, reported the Reuters news agency.

“At some point I will have to, I’m pretty sure about it, but so far it hasn’t been mandatory to compete, so I haven’t done it, no,” added Tsitsipas, who reached the French Open final in June but was bounced in the first round at Wimbledon where he said he didn't like living and competing in an isolated bubble.

World number one Novak Djokovic said in April he hoped the Covid-19 vaccine would not become mandatory for players to compete and has declined to answer questions regarding his own vaccination status.

But other tennis greats and Grand Slam winners Roger Federer and Rafa Nadal feel athletes need to be vaccinated to help beat the pandemic and try to return life and sports to some sense of normality.

Federer said in May that he received the Pfizer-BioNTech vaccine, while Nadal said: “The only way out of this nightmare is vaccination. Our responsibility as human beings is to accept it.

“I know there is a percentage of people who will suffer from side effects, but the effects of the virus are worse,” he also said.

Spectators will not be allowed to attend qualifying rounds at this month’s U.S. Open because of the lingering Coronavirus, the United States Tennis Association (USTA) said after previously saying that they would.