KEY BISCAYNE, FL - APRIL 03: Novak Djokovic of Serbia defeats Kei Nishikori of Japan after their match during the mens final on Day 14 of the Miami Open presented by Itau at Crandon Park Tennis Center on April 3, 2016 in Key Biscayne, Florida...People: Novak Djokovic..

FILED - 12 November 2019, England, London: Serbian professional tennis player Novak Djokovic reacts during the singles match against Dominic Thiem on day three of the Nitto ATP Finals at The O2 Arena. Djokovic on Tuesday said he has tested positive for coronavirus, becoming the sixth patient infected in an exhibition series he organized. Photo: John Walton/PA Wire/dpa

KEY BISCAYNE, FL - APRIL 03: Novak Djokovic of Serbia defeats Kei Nishikori of Japan after their match during the mens final on Day 14 of the Miami Open presented by Itau at Crandon Park Tennis Center on April 3, 2016 in Key Biscayne, Florida...People: Novak Djokovic..