On Wednesday, David Goffin announced on Instagram that he has tested positive for COVID-19.
Goffin is coming off a first-round exit at Roland Garros, where he fell to eventual quarterfinalist Jannik Sinner, 7-5, 6-0, 6-3.
The 29-year-old Belgian, who said he is "feeling good up to now," was set to compete in St. Petersburg next week, but was forced to withdraw from the tournament.
"I will quarantine," added Goffin, "and if everything goes well I will be back in Antwerp!"
Alexander Zverev, who also lost to Sinner in the fourth-round of Roland Garros, felt some coronavirus-like symptoms after his loss last week.
"I'm completely sick,” the German told press after his loss. “I can't really breathe, as you can hear by my voice. I had fever, you know, as well. I'm not in the best physical state, I would say. I think that had a little bit of an effect on the match today."
Though players are required to report any symptoms to tournament officials, Zverev did not, per reports.
However, According to the French Tennis Federation, Zverev was caught up on his mandatory tests, and those results came back negative.
"Zverev is up to date on his tests, which have all been negative," the statement read. "His last test was on September 29, with results received on September 30. Today he received a reminder for his next test, to be carried out within five days of the previous results. He did not consult the tournament doctors before his match."