Novak Djokovic's father defended his son on Wednesday and blamed Grigor Dimitrov for the spreading of the coronavirus at a series of exhibition matches hosted by the men's world number one.
Djokovic and his wife tested positive for the virus on Tuesday.
The 17-time Grand Slam champion then apologized online for organizing the Adria Tour events, which brought together professional players from various countries to play matches in Serbia and Croatia.
Thousands of spectators attended the matches and no social distancing was observed.
"Why did it happen? Because that man (Dimitrov) probably came sick, who knows from where," Srdjan Djokovic told RTL Croatia TV.
"He didn't test here, he tested somewhere else... I think that's not fair. He inflicted damage to both Croatia and to us as a family in Serbia," he added.
Dimitrov, a three-time Grand Slam semifinalist from Bulgaria, was the first Adria Tour participant to test positive for the virus.
He was followed by Borna Coric and Viktor Troicki.