But he apologised after footage of the players dancing in proximity to each other in a nightclub was beamed around the world.
"I deeply apologise to anyone that I have potentially put at risk by playing this tour," the 23-year-old said in a statement. "I will proceed to follow the self-isolating guidelines advised by our doctors. As an added precaution my team and I will continue with regular testing."
The latest footage has been condemned by the tennis world.
"This is my concern with tennis attempting to come back mid-pandemic: not that precautions can't be taken, but that too many tennis players are conditioned to be wildly self-centred and have no concept of how to act for the greater interest of a larger group," NY Times tennis writer Ben Rothenberg said.
"Philipp Plein has already deleted the frame of his Instastory that most clearly showed Zverev partying today. No matter how lazy, sloppy and selfish players are about following public health guidelines mid-pandemic, they sure can spring to quick action to cover their asses."
Zverev has also signed up to play in a Berlin tennis tournament in July that will allow crowds of up to 1000 fans in the stands.
There will be two events in the German capital — one outdoors at the Steffi Graf Stadium and one indoors at the city's historic Tempelhof Airport.
"When we host the tournament in mid-July, there will be a strict hygiene concept that we will co-ordinate with the Berlin Senate," tournament director and German Fed Cup skipper Barbara Rittner told Deutsche Welle.
"We will have around 1000 spectators at the Steffi Graf stadium and around 300 in the hangar at Tempelhof.
"It will be important to carefully observe all regulations and to test the players beforehand. This is one of the requirements for these events. We will treat the situation and regulations very respectfully."
Around 4000 spectators watched the Belgrade event of the Adria Tour where there was no social distancing. Players were also photographed shirtless, dancing the night away at a packed Belgrade club.
Australian player Nick Kyrgios described the staging of the event as "boneheaded".
But when asked about whether player behaviour could threaten the US Open, tournament director Stacey Allaster said she had "a lot of confidence in these professional athletes".