Novak Djokovic announced he tested positive for the coronavirus after playing in the Adria Tour Exhibition in the Balkan region over the weekend.
Borna Coric of Croatia, Grigor Dimitrov of Bulgaria and Viktor Troicki also tested positive after the tournament.
The final between Djokovic and Andrey Rublev was called off on Sunday after Dimitrov announced he tested positive. Djokovic was criticized by others in the tennis community for moving forward with the tournament without any social distancing measures. He has also expressed his skepticism toward a vaccine if it became available and mandated to travel on tour.