World No 1 Novak Djokovic has said participating in the US Open would be an impossible task due to the "extreme" coronavirus protocols in place for the tournament at Flushing Meadows.
The US Open, scheduled to begin on August 31, will be the first Grand Slam to be played after the Covid-19 pandemic suspended the season in March. The French Open was postponed to September while the Wimbledon Championships was cancelled.
The suspension of the tennis season was last extended until the end of July but Djokovic, a three-time champion in New York, is not sure the tournament will go ahead.
"I had a telephone conversation with the leaders of world tennis. There were talks about the continuation of the season, mostly about the US Open due in late August, but it's not known whether it will be held," Djokovic told Serbia's Prva TV.
"The rules that they told us that we would have to respect to be there, to play at all, they are extreme. We would not have access to Manhattan, we would have to sleep in hotels at the airport, to be tested twice or three times per week.
"Also, we could bring one person to the club which is really impossible. I mean, you need your coach, then a fitness trainer, then a physiotherapist."
Djokovic suggested economic factors were behind the push to play the tournament.
"They want the tournament to go ahead at any cost for economic reasons, which I understand," he said. "But the question is, how many players are willing to accept those terms."
World No 2 Rafa Nadal had also said he would not travel to the US in the present circumstances.
Nadal has also questioned whether tennis can restart with the pandemic still gripping large parts of the world and unless every player is able to compete.
"For me is very difficult to separate the status that the world is living from my real perspective on the world of tennis, no?" Nadal said this week.
"We need to be responsible, we need to be sure that the situation is safe enough, and then of course try to come back to our tour when the things are clear."