Serena Williams says she is still planning to play this month's US Open and the French Open in September.
The rescheduled French Open starts on 27 September at Roland-Garros in Paris.
"I see myself doing it all if it happens," said 23-time Grand Slam champion Williams.
Williams is set to play in the WTA Top Seed Open in Lexington, Kentucky next week as preparation for the US Open, which she has won six times.
Barty and Svitolina pulled out of the US Open because of concerns over travelling to the United States during the coronavirus pandemic, while Bertens, from the Netherlands, withdrew because of Dutch government regulations that require people returning from the US to quarantine for two weeks.