Under-fire Alexander Zverev announced his withdrawal on Wednesday from a tennis tournament in Berlin next week with the German at the centre of a war-of-words between Nick Kyrgios and Dominic Thiem, who are still due to play in the German capital.

"I was planning this month to play in Berlin, but I have made the decision to stay put and train with my team and not play any tournaments at the moment," Zverev, ranked seventh, wrote on social media. "It's never nice to miss the chance to play at home, but I will be back soon," added Zverev who said that ex-pro David Ferrer has joined his coaching team on a trial basis.

Earlier on Wednesday, the organiser of the invitational exhibition tournament in Berlin, which starts Monday, had said he doubted Zverev would play. Even with Zverev out, the presence of Kyrgios and Thiem in Berlin could provide an explosive mix with tensions running high.

Recent footage of the 23-year-old German partying in a busy bar despite pledging to "follow self-isolating guidelines" after playing in Novak Djokovic's coronavirus-hit Adria Tour sparked a spat between Kyrgios and Thiem. "How selfish can you be?" Kyrgios wrote on Instagram at the time.

On Wednesday, Kyrgios said Austria's Thiem wasn't on the same "intellectual level" after the Austrian called his criticism "cheap" and claimed it was "bad luck" that Zverev was caught partying after promising to self-isolate.

Last week Kyrgios also exchanged verbal jabs with German legend Boris Becker, who called him a "rat" for singling out Zverev. Zverev said Wednesday that he has returned a third negative test result for COVID-19.