Andy Murray has called on more of his fellow tennis players to get vaccinated as the US Open's double standards on the issue was called into question.
Unlike roughly half the other men and women who will be taking the court when the year's final grand slam tournament begins on Monday, Murray has been vaccinated against Covid-19.
'THINGS I DID WRONG': Naomi Osaka's mental health admission
'NOT CLOSE': Aussie great's Ash Barty truth bomb for Naomi Osaka
And the Scottish veteran wishes more tennis pros were.
"The reason why all of us are getting vaccinated is to look out for the wider public," Murray said on Saturday in New York.
"We have a responsibility, as players who are travelling across the world, to look out for everyone else as well.
"I'm happy that I'm vaccinated. I'm hoping that more players choose to have it in the coming months."
Players and their team members at the US Open do not need to be vaccinated to take part.
However the spectators - above the age of 12 - must be able to prove they have had at least one shot in order to gain entry.
The New York City mayor's office on Friday mandated proof of vaccine to enter Arthur Ashe Stadium, the main venue for primetime matches.
The United States Tennis Association then elected to extend the vaccine requirement to all attendees aged 12 years and older at the Billie Jean King National Tennis Centre, regardless of which facilities ticket-holders plan to access.
But in a seemingly hypocritical move, the USTA confirmed the mandate does not apply to athletes competing in the tournament, some of whom have previously expressed reluctance to receive the shot.
Djokovic and Tsitsipas opposed to mandatory vaccinations
World No.3 Stefanos Tsitsipas, who will face the unseeded Murray in the first round on Monday, has said he is wary of getting vaccinated.
The Greek star has previously said he and will only do so if it becomes mandatory to compete on the ATP Tour.
World No.1 Novak Djokovic - who contracted coronavirus last year - this week reiterated his position that he hoped the vaccine would not become mandatory for players to compete.
He has declined to answer questions about his own vaccination status.
But fellow 20-time grand slam winners Roger Federer and Rafael Nadal feel athletes need to play their part and get vaccinated.
Some players say their itinerant lifestyle, regularly travelling from city to city - or even continent to continent - makes getting the vaccine complicated.
French veteran Gilles Simon, who previously declared who wouldn't get vaccinated because he "wasn't scared" of Covid, was forced to withdraw from the US Open on Saturday when his coach tested positive.
It serves as a brutal irony for Simon, who conceded the 2021 tournament may have been his final US Open before retirement.
Fans and commentators were quick to point out the double standards of barring unvaccinated spectators, but allowing players to compete.
— NYECHO (@nyecho) August 28, 2021
— NYECHO (@nyecho) August 28, 2021
— Layla Gates (@summersnow1990) August 28, 2021
I understand why but to require fans proof of vaccination & let some players play who aren't you clearly are showing a double standard. You going "all out" like this should b for players too. No favortism... Otherwise you just opened a "pandora's box"
— sportsguy49 (@nikesportsguy49) August 28, 2021
How hypocritical of the US Open to require fans be vaccinated but not the players. Djokovic and then you have players that are of 45 supporters like Isner, Sock & Johnson. There are players from the GOP states who might be supporting their Governor. It's just crazy!
— Lisa Knott (@chanel_glasses) August 28, 2021
Click here to sign up to our newsletter for all the latest and breaking stories from Australia and around the world.