World number five Elina Svitolina and world number seven Kiki Bertens are the latest players to pull out of the US Open.
Svitolina and Bertens have followed in the footsteps of Rafael Nadal and women's world number one Ashleigh Barty in deciding against playing in the New York grand slam event due to fears over Covid-19.
Svitolina said in a statement on Twitter: "I understand and respect all the the efforts they are putting to make it happen in a safe environment, but I still don’t feel comfortable to travel to US without putting my team and myself at high risk."
— Elina Svitolina (@ElinaSvitolina) August 7, 2020
Bertens took to Instagram and posted: "The situation around Covid-19 is still worrying and the health of everyone and the control over this virus is priority."
The US Open organisers are creating a biosecure bubble in New York to hold the tournament from 31 August without spectators. But concerns remain about whether players would face mandatory quarantines upon returning home.
Former world number one Andy Murray, who won the US Open in 2012, said that players travelling to New York needed assurance that they would not face mandatory quarantines after returning to Europe.
"Our prime minister indicated yesterday that we should be quarantined for 14 days after coming back from the States," Bertens said.
"Of course we respect this as a team and this would disturb our preparation for my beloved claycourt tournaments in Rome and Paris."
The Italian Open is scheduled to be held in Rome from 20 September ahead of the French Open in Paris a week later.
