Rafael Nadal says Novak Djokovic will need to be vaccinated to keep playing if tennis bodies make coronavirus shots obligatory once they become available.
Nadal told Spanish newspaper La Voz de Galicia this week that Djokovic and all players will have to follow the rules when tennis eventually returns to action.
Nadal said no one can be forced to take the vaccine and everyone should be free to make their choices, but all players will have to comply if tennis officials require "vaccination to travel" and to "protect" everyone.
Djokovic recently said he was against taking a vaccine for the coronavirus even if it became mandatory to travel. He later said he was open to changing his mind.
"Djokovic will have to be vaccinated if he wants to keep playing tennis at the top level," Nadal said. "If the ATP or the International Tennis Federation obligates us to take the vaccine to play tennis, then we will have to."
Meanwhile, US Open champion Bianca Andreescu is remaining focused on her goal to climb to the top of the women's rankings.
Andreescu, currently ranked sixth in the world, won her first WTA title at Indian Wells last year and then beat Serena Williams in the finals at Toronto and again at the US Open in Flushing Meadows to clinch her first Grand Slam crown.
But her climb up the rankings was halted after she injured her left knee at the WTA Finals last October.
She has not played since and her bid to return to competitive tennis suffered a further jolt when the season was halted in March due to the coronavirus.
"I have only been working out right now," said Andreescu, who turns 20 next month.
"It is tough here in Toronto because they even closed the parks. So, nobody can play any tennis, basketball or even sit on a bench. But I have been working in my mind as much as I can.
"It is a very powerful tool that I like to use. I don't know what the future has to hold but I'm going to give my best. I don't like losing so we'll see but that's definitely the goal, as is every other Grand Slam as well."