Croatia's Borna Coric announced on Monday he has tested positive for coronavirus after playing in an exhibition tournament in Croatia featuring world number one Novak Djokovic.
"Hi everyone, I wanted to inform you all that I tested positive for COVID-19," the top 50 player posted on Twitter.
On Sunday, another player, Grigor Dimitrov, said he had also tested positive after pulling out of the exhibition event.
Coric said: "I want to make sure anyone who has been in contact with me during the last few days gets tested!
"I am really sorry for any harm I might have caused! I'm feeling well and don't have any simptoms (sic). Please stay safe and healthy! Lots of love to all!"
Coric had beaten Dimitrov in the second leg of the Adria Tour in Zadar on Croatia's Adriatic coast on Saturday.
Dimitrov withdrew from the Balkans tournament following that match, complaining of feeling unwell, and on Sunday announced he had tested positive.
Sunday's final between Djokovic and Russia's Andrey Rublev was immediately cancelled as a precaution.
