An unnamed player has tested positive for coronavirus shortly before the resumption of the WTA Tour at the Palermo Open in Italy.
The player, who has no symptoms, has withdrawn from the tournament.
The WTA says the event, which marked the return of professional tennis for the first time since March, will continue.
“All those who may have been in close contact with the individual are undergoing testing,” added the WTA.
The news of the positive test broke shortly before play in the event’s qualifying started in the Sicilian capital on Saturday.
Few of the world’s leading players are taking part, with Romania’s world number two Simona Halep and British number one Johanna Konta among those to have pulled out.
“Any individual who tests positive will remain in isolation until cleared by a physician per the established protocols and will receive proper medical treatment,” added the WTA.
The men’s ATP Tour is set to return later this month with the Cincinnati Masters, which is also a WTA event.
That tournament is being held in a safety bubble in New York from 22 August, immediately before the US Open takes place at Flushing Meadows on 31 August.