Djokovic announced the diagnosis of he and his wife Jelena on Tuesday, releasing a statement to social media saying that he was "extremely sorry for each individual case of infection" which may have resulted from the controversial tournament.

The Serb now becomes the fourth professional to have contracted the virus in the wake of the tour, which took place in Belgrade and Zadar, and comes after similar test results from Grigor Dimitrov, Borna Coric and Viktor Troicki.

The tour had caused a torrent of criticism online as organizers pushed forward with plans to hold matches in stadia filled with fans, while Djokovic was also slammed for video footage which appeared online in which he was seen dancing at a nightclub alongside other players. 

The positive test comes after Kyrgios had publicly criticized Djokovic for hosting the tournament, and the vocal Australian was among the first professionals to react to Tuesday's news.

Others pointed out online that it is a strange sight for Kyrgios, one of the sport's most colorful characters, was the voice of reason amid the ongoing coronavirus global health crisis.