World No. 5 Elina Svitolina and No. 7 Kiki Bertens both withdrew from the U.S. Open on Friday.
Svitolina was a semifinalist last year before losing to Serena Williams.
The two join World No. 1 Ashleigh Barty of Australia on the list of women's players who have decided not to play due to concerns involving the coronavirus pandemic. Barty dropped out late last month. Defending men's champ Rafael Nadal also is skipping the tournament in New York.
Svitolina, from Ukraine, also cited travel concerns during her announcement Friday morning on her Twitter account.
"Considering all the aspects, I have decided not to play the US Open 2020," Svitolina wrote. "I want to thank the USTA, organizers and the WTA for giving the players a chance to play and the fans a chance to watch this great event.
"I understand and respect all the efforts they are putting to make it happen in a safe environment, but I still don't feel comfortable to travel to the US without putting my team and myself at high risk."
Bertens, from Netherlands, also expressed concern over COVID-19 and traveling to the United States.
"After long consideration I have decided not to go to the States for Cincinnati and the U.S. Open," said Bertens, referencing the Western Southern Open played in August. "The situation around COVID-19 is still that worrying and the health of everyone and the control over this virus is priority. Our prime minister indicated yesterday that we should be quarantined for 14 days after coming back from the States. Of course we respect this as a team and this would disturb our preparation for my beloved clay court tournaments in Rome and Paris."
The U.S. Open is slated to begin on Aug. 31.
--Field Level Media