There have been just over 12,000 confirmed cases of coronavirus in Serbia, causing 252 deaths, and the government recently loosened lockdown restrictions. During the week 20,000 fans turned up to a football match in Belgrade but people are still advised to stay 1m apart from each other.
Djokovic had no issues holding his event, even in today's climate. Nor did he have a problem getting close with his rivals.
"We have different circumstances and measures so it's very difficult to think of international standards," Djokovic said, adding Serbia has "better numbers" compared to other countries when it comes to the global pandemic.
"You can also criticise us and say this is maybe dangerous but it's not up to me to make the calls about what is right or wrong for health.
"We are doing what the Serbian government is telling us and hopefully we soon will get back on tour collectively.
"Of course, lives have been lost and that's horrible to see, in the region and worldwide. But life goes on, and we as athletes are looking forward to competing."
Despite his optimism, many in the tennis world were shocked at what they saw in Belgrade.
Commentator Nick McCarvel couldn't believe the "shocking" scenes, while British tennis writer Mike Dickson questioned the double standards of players voicing their fears about the US Open but interacting so closely at the Adria Cup.
Rene Denfeld wrote on Twitter: "Obviously, no social distancing at the press conference. Fans courtside, no social distancing.
"Different countries, different stages of the pandemic but after months of avoiding human contact like crazy, an event like this is a super jarring sight."
New York Times tennis writer Ben Rothenberg said: "Watching the all the human closeness and hugging at Adria Tour, you'd almost forget why the Adria Tour exists in the first place.
"Hope it goes well, but golly does seeing crowds like this make me nervous in June 2020."
The US Open is planning on implementing strict biosecurity protocols to ensure the tournament can go ahead safely, such as players only being allowed to bring one member of their entourage, but those at the Adria Cup continued to question whether the grand slam would be feasible.
Speaking in Belgrade, Zverev said it's "gonna be very difficult … I don't think a lot of players will feel comfortable in the circumstances" while Thiem added "some circumstances would have to change to make sense to go there".
Grigor Dimitrov said the conditions need "to be safe and make sense for all the players … health above all".
Djokovic has suggested he might skip the US Open and restart his season on clay in September.
"Most of the players I have talked to were quite negative on whether they would go there," he said during the week.
"For me currently, as things stand, most probably the season will continue on clay at the beginning of September."
