Zverev was part of the ill-fated Adria Tour hosted by world number one Novak Djokovic, who tested positive for the coronavirus after not following distancing and other safety protocols during the event.
Zverev's team have yet to respond to a request from Reuters for comment.
"I deeply apologise to anyone that I have potentially put at risk by playing this tour". He said in his social media post that he will "follow the self-isolating guidelines by our doctors" and will get regularly tested.
While Zverev tested negative, he released a statement afterwards vowing to self-isolate, only to be spotted at a busy bar, apparently over the weekend, in footage that went viral.
"One that stuck out for me was seeing "Sacha" Zverev again man, again, again, how selfish can you be?" he said on Instagram Monday.
"Seeing Sascha Zverev again, again, how selfish can you be?" How selfish can you be? I mean if you have the audacity to f*** put out a tweet you make it manage right on saying you are going to save lives for 14 days and apologizing to the f*** general public to put their health at risk. My God. Have your girlfriend for f*** 14 days.
"To be honest, like the rest of the world, I'm a little confused".
All that came to a crashing halt when several players, inducing Djokovic, and staff members tested positive for Covid-19, and Paul Annacone, a seasoned and respected coach, understands the criticism. Meanwhile, Djokovic's coach Goran Ivanisevich has reported the corona test and has also been found positive.