Following this jibe, a war of words broke out between Kyrgios and Becker. The Australian also called the veteran tennis star as a 'doughnut'.
Zverev had promised to undergo self-isolation upon returning from the controversial Adria Tour but some videos of Zverev partying in the French Riviera surfaced and it made Kyrgios criticised the player for being irresponsible.
Kyrgios released a video on his Instagram account, accusing Zverev of being selfish and taking note, Becker replied: "Don't like no #rats! Anybody telling off fellow sportsman/woman is no friend of mine! Look yourself in the mirror and think you are better than us."
Becker's tweet did not go down well with Kyrgios and the Aussie star replied: "For goodness sake Boris, I'm not competing or trying to throw anyone under the bus. It's a global pandemic and if someone is as idiotic as Alex to do what he has done, I'll call him out for it. Simple."
The Aussie star also said that the word 'rat' was totally uncalled for as he is just holding someone accountable for their actions.
"@TheBorisBecker is a bigger doughnut than I thought, can hit a volley, obviously not the sharpest tool in the shed though," Kyrgios said in another tweet.
Earlier, world number one Novak Djokovic had announced that he and his wife Jelena had contracted coronavirus.
However, their children tested negative for COVID-19, Djokovic had said.
Moreover, Croatia's player, Borna Coric, also tested positive for coronavirus. At that time, he was the second tennis player to test positive for COVID-19 after Bulgaria's Grigor Dimitrov.
Both the tennis stars had taken part in the charity tennis tournament organised by Djokovic.
The charity tennis tournament, known as Adria Tour, was heavily criticised from all around the corners for going ahead during a pandemic.
The final of the Adria Tour in Zadar was cancelled after Dimitrov tested positive for coronavirus. (ANI)