Djokovic among four players to test positive as concern grows for tennis' August restart

Novak Djokovic on Tuesday became the fourth player to test positive for the novel coronavirus after competing in his own Adria Tour exhibition event in Serbia and Croatia.

The diagnosis comes as a major embarrassment for the Serbian world No 1－whose wife Jelena also tested positive－and raises serious concerns for tennis' governing bodies in their bid to restart the sport after a lengthy shutdown.

"The moment we arrived in Belgrade we went to be tested. My result is positive, just as Jelena's, while the results of our children are negative," Djokovic said in a statement.

Earlier on Tuesday, Viktor Troicki said he and his pregnant wife have both been diagnosed with the virus, while Grigor Dimitrov said on Sunday he tested positive. Borna Coric played Dimitrov on Saturday in Zadar, Croatia, and said on Monday he had tested positive.

The professional circuit was halted in early March as nations closed borders and imposed lockdowns to contain the spread of the virus.

Last week the men's ATP and the WTA, which runs women's events, issued revised calendars for the resumption of the circuit from August while organizers of the US Open said the Grand Slam will be staged without fans as scheduled from Aug 31 to Sept 13 in New York.

Those plans, however, may need to be redrawn after the four players' positive tests.

The players did not break any Serbian or Croatian government protocols as neither country required them to maintain any social distancing. However, the fact that four players and some support staff caught the virus highlights the risks of athletes from different countries being in close proximity to each other.

"I want to make sure anyone who has been in contact with me during the last few days gets tested," Coric, ranked No 33 in the world, said on Twitter. "I am really sorry for any harm I might have caused. I'm feeling well and don't have any symptoms."

Troicki played in the first leg staged at Djokovic's tennis complex in central Belgrade from June 13-14, before Dimitrov and Coric tested positive at the second leg in Zadar held from June 20-21.

Troicki, 34, entered Janko Tipsarevic's Eastern European Championship tournament which started in Belgrade last Monday and pulled out after learning that he and his wife tested positive.

"My wife took the test on Friday and I took it on Sunday after she tested positive," Troicki told Serbia's Telegraf website. "Our daughter tested negative."

The ATP wished players and staff who tested positive a speedy recovery and urged "strict adherence to responsible social distancing".

The governing body added that it will implement a variety of precautions and protocols that would be adjusted as and when dictated by the latest medical information to ensure safety at events when the tour resumes on Aug 14.

Bulgarian Dimitrov flew in to play in Djokovic's event in Belgrade and the second leg, as did other top names like world No 3 Dominic Thiem of Austria and Germany's seventh-ranked Alexander Zverev.

Organizers of other sports looking to resume from the coronavirus shutdown will be watching developments with some trepidation as they try to find the safest way of getting competition back underway.