- Novak Djokovic tests positive for Covid-19, 'extremely sorry'
- Novak Djokovic's brother: Covid-19 backlash 'worst possible scenario'
Djokovic was criticised for hosting the tournament amid a pandemic after Grigor Dimitrov, Borna Coric and Viktor Troicki also returned positive tests after playing in the tournament that was held in Serbia and Croatia.
Nick Kyrgios hits back at Borna Coric on Adria Tour - 'Do you have rocks in your head?'
Here are some of reactions from the tennis world to the Serb's positive test...
Nick Kyrgios, two-times Grand Slam quarter-finalist
Martina Navratilova, 59-times Grand Slam champion
Patrick McEnroe, former doubles champion and commentator said in a video:
"When I sent out a tweet a couple weeks ago about that event in Serbia I said yeah it looks like a normal tennis event to me. I'm not sure everyone got my point, maybe they are starting to get it now. Nothing's foolproof so don't be foolish. That's my message."
Over the past two days, organisers have also been criticised for allowing stands to be packed with fans during the opening leg in Belgrade.
With no social distancing rules in place in Serbia, players hugged at the net, played basketball, posed for pictures, attended press conferences and were out dancing together.
'We did all we could' - Adria Tour organisers react to Grigor Dimitrov's positive coronavirus test
British number one Dan Evans
He said: "I don't think he should be having a players' party and dancing all over each other, Players have tested positive. He should feel some responsibility in his event and how it's transpired, really.
"It's very unfortunate that Grigor has it and Coric has it but you strip it back, is it a surprise? I think that's the question we should all ask."
Australian Open quarter-finalist Tennys Sandgren
American tennis player Sachia Vickery
American tennis player Mitchell Krueger
Noah Rubin, former junior Wimbledon champion
British tennis player Tara Moore
Dominic Thiem defends Novak Djokovic: 'He didn't break any law'
Novak Djokovic: Criticism after Adria Tour a witch-hunt