Nick Kyrgios let rip at "selfish" fellow tennis star Alexander Zverev after the German was seen partying despite promising to self-isolate following Novak Djokovic's coronavirus-hit Adria Tour. Zverev was part of the exhibition event organised by the world No 1 where social distancing was minimal, matches took place in front of thousands of fans and players were even seen at a nightclub, despite the pandemic. Djokovic, Grigor Dimitrov, Borna Coric and Viktor Troicki all subsequently tested positive for Covid-19. 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. Kyrgios, who had slammed the decision to hold the Adria Tour as "bone-headed", said he was unhappy with the behaviour of some of the biggest names in the sport. "So I wake up and I see more controversial things happening all over the world. One that stuck out for me was seeing 'Sacha' Zverev again man, again, again, how selfish can you be?" he said on Instagram. "If you have the audacity to put out a tweet that you made your management write on your behalf saying you're going to self-isolate for 14 days and apologising to the general public for putting their health at risk, at least have the audacity to stay inside for 14 days, my god." The flamboyant Australian added: "This tennis world ... seriously how selfish can you all get?" Zverev and Kyrgios, two of the most exciting players on tour, have history. Ahead of this year's Australian Open, Zverev hit out at Kyrgios, who had provocatively performed push-ups when the German was serving double faults during the ATP Cup. "I think there's a lot of young guys that are right now, no offence, just better than him," said Zverev, playing down Kyrgios's chances of winning a Grand Slam.