The fallout from Novak Djokovic’s safety-flouting Adria Tour exhibitions worsened Tuesday, when the world’s top-ranked tennis player disclosed he has become the fourth participant to test positive for the novel coronavirus.

Djokovic, 33, organized the Adria Tour to give himself and fellow pros a chance to compete after being idle since March, when the men’s and women’s pro tours were suspended.

But it has proved calamitous, resulting in at least six other positive tests: fellow players Grigor Dimitrov, Borna Coric and Viktor Troicki; Djokovic’s wife, Jelena; Djokovic’s fitness coach; and Dimitrov’s coach.

The exhibitions were staged without following basic health and safety protocols to guard against transmission of the highly contagious virus, which has infected more than 9 million and killed at least 472,000 worldwide.

Djokovic announced his positive result in a statement Tuesday morning, explaining that his family was tested upon returning to Belgrade after the tour stop in Croatia.

“My result is positive, just as Jelena’s, while the results of our children are negative,” Djokovic wrote, adding that he intends to self-isolate for 14 days.

Originally scheduled over four weeks in three Balkan countries, the Adria Tour kicked off with a news conference in Belgrade that included Djokovic, third-ranked Dominic Thiem, seventh-ranked Alexander Zverev and 19th-ranked Dimitrov seated side by side, without protective face masks, while fielding questions from several rows of reporters who also were not wearing masks.

On the court, there was no apparent effort to keep players from shaking hands or draping arms around one another following matches. And off the court, they danced and partied shirtless at a Belgrade nightclub.

Australia’s Nick Kyrgios was among the players who chose not to take part in the exhibition. He called it “boneheaded” Monday, after Coric became the second player to disclose his positive test.

On Tuesday, the 25-year-old Kyrgios, who has been roundly criticized for his combustible temperament, shared footage on Twitter of a shirtless Djokovic and other Adria Tour players dancing at a nightclub, writing: “Prayers up to all the players that have contracted Covid-19. Don’t @ me for anything I’ve done that has been ‘irresponsible’ or classified as ‘stupidity’ — this takes the cake.”

Also Tuesday, the remainder of the Adria Tour, which was to run through July 5 with a final stop in Bosnia, was canceled.

In the aftermath, the multiple bodies that govern international tennis — including the men’s and women’s pro tours, the International Tennis Federation and the national federations that stage the U.S., French and Australian opens — must think deeply about plans to restart the pro tours in mid-August.

This much is clear for all sports, amateur and professional: The Adria Tour debacle demonstrates the peril of letting athletes decide when it’s “safe” for sports to resume, and it underscores the imperative of having public-health officials dictate the terms.

In a text message, former U.S. Davis Cup captain Patrick McEnroe, now an ESPN commentator who recently recovered from the coronavirus, wrote, “We all understand that no plan for coming back to normal from covid-19 is foolproof, but let’s not be foolish along the way back.”

The men’s pro tour is scheduled to resume with Washington’s Citi Open on Aug. 14. The remaining Grand Slam events on the 2020 calendar — the U.S. Open and the deferred French Open — are scheduled to start Aug. 31 and Sept. 27, respectively.

In a telephone interview Tuesday, Washington-based venture capitalist Mark Ein, who manages the Citi Open, said the experience of the Adria Tour validates the strict protocols that will be in place for the Citi Open as well as the Western & Southern Open and the U.S. Open, which will follow in New York.

“Everybody recognizes that the issue isn’t ‘Can you come back to sports?’ but ‘How [do] you come back to sports?’ ” Ein said. “What we saw in that tour was the textbook case of how not to come back. What we’re going to show in Washington and the other U.S. events is how you should come back.”

Ein said he continues to field calls from agents of players who want to be part of the Citi Open’s 48-player draw.

“If there is a silver lining in this, I think it will make players just that much more cautious,” Ein said. “I don’t think it impacts their desire to get back to doing what they love, but it makes clear that they need to do their part to do it in the safest possible way.”

Djokovic, who boasts 17 Grand Slam titles to Rafael Nadal’s 19 and Roger Federer’s men’s record 20, devoted the bulk of his statement acknowledging his diagnosis to defending his rationale for flouting safety protocols in staging the event, underscoring his charitable intent.

“It was all born with a philanthropic idea, to direct all raised funds towards people in need, and it warmed my heart to see how everybody strongly responded to this,” the statement read. “We organized the tournament at the moment when the virus has weakened, believing that the conditions for hosting the Tour had been met. Unfortunately, this virus is still present, and it is a new reality that we are still learning to cope and live with.”

He wrote that he was “extremely sorry” for each case of the virus and expressed hope that it would “not complicate anyone’s heath situation and that everyone will be fine.” But he did not take responsibility for the spread of the virus among his peers and, potentially, among the thousands of spectators who packed grandstands for the matches in Serbia and Croatia, few of them wearing masks.

Djokovic has criticized as “extreme” the extensive safety protocols announced for the U.S. Open, including testing players upon arrival and weekly, limiting them to one companion on match days (a coach, physical trainer or significant other) and urging them to stay in one of two designated hotels outside Manhattan and near the tournament grounds at the USTA Billie Jean King National Tennis Center in Queens.