Tennis great Boris Becker has explained why he came at Nick Kyrgios in an ugly Twitter spat, calling the Aussie a “rat” for slamming the irresponsible behaviour of some players during the coronavirus pandemic.

Kyrgios’s criticism of ‘selfish’ Alexander Zverev’s partying antics in Monaco immediately following the German’s contrite vow to self-isolate amid the drama of the Novak Djokovic-led Adria Tour coronavirus cluster. But Kyrgios’ Instagram video ripping into Zverev did not go down well with Becker.

“We all live in the pandemic called #Covid_19 ! It’s terrible and it killed to (sic) many lives…we should protect our families/loved ones and follow the guidelines but still don’t like #rats @NickKyrgios @farfetch,” Becker tweeted.

What ensued was a feisty back-and-forth between Kyrgios and Becker in which the Aussie returned serve, calling the six-time grand slam champion a “doughnut”, and “not the sharpest tool in the shed”.

In an attempt to explain his reasoning for attacking Kyrgios later in the evening, Becker revealed that he felt the Canberran had broken some sort of tennis players’ code, despite Zverev’s partying video being posted publicly on social media.

“There is an unspoken understanding between athletes! Whatever happens on the court stays there including the lockers! Nobody will talk about it … #respect #sport #fellowship,” Becker said.

Becker then turned the debate on Kyrgios’ up-and-down on-court form on the ATP Tour, telling him to “man up”.

“I really would like to see @NickKyrgios fulfill his potential and win a grand slam! He would be an incredible role model for for the youth of the world addressing the issues of equality/race/heritage! Man up buddy and deliver!” Becker said.

Kyrgios fired back at the 52-year-old.

“Why are you now talking about tennis? It has nothing to do with tennis? How about the dude who you are defending mans up and gives us some sort of explanation? Not another average management apology,” he tweeted.

In replies to some irate fans, Becker suggested that Kyrgios’ wrongdoing was publicly calling out Zverev instead of talking to him privately. Becker did say that Zverev “should be ashamed” for his actions though.

“@AlexZverev broke the quarantine rules and he should be ashamed of himself! He is a role model for many tennis fans a bright star on the horizon but still don’t like rats … #word,” he tweeted.

In another exchange with a German fan who was clearly unimpressed with the response to Kyrgios, Becker said: “Unfortunately you have no idea what it’s about … but fortunately we live in democracy!”

And in a retweet Becker seemingly endorsed the Serbian Prime Minister shifting blame from Djokovic and putting responsibility for the Adria Tour controversy on the government not the world no.1.

Kyrgios has openly shared his skepticism about tennis’ eagerness to return amid the COVID-19 pandemic, including the US Open’s decision to go ahead in New York from August 31.

Kyrgios also called Djokovic spearheading the ill-fated Adria Tour in the Balkans as a “boneheaded decision”, and told his many critics not to target him \

Speaking to Australian blog Basketball Forever last night, Kyrgios said that the tennis community were not being patient enough considering the life and death scenario at play around the world.

“At this stage I think tennis is way too risky, especially with the new cases i saw the other day in the States. It’s pretty hectic,” Kyrgios said in an Instagram live video.

“I think we’re forcing it a little bit too much. If we saw a gradual decline in cases, and deaths going down … [but] there’s still cases in Australia. In Victoria there was a balloon of cases yesterday that just popped up and it shows it’s not a joke.

“I feel like the tennis world isn’t taking it seriously enough.

“With all the stuff going on with Djokovic and other players, people think I’m attacking these players, but I just think people aren’t taking it serious. People are, like, losing their lives, their families over this, do you know what I mean? It’s not a joke.

“I’m not sure if a global sport like tennis, where athletes come from all over the world, I don’t think it’s the right time to play it.”