Other than a friendship with Andy Murray, the outspoken Kyrgios has never gone out of his way to play nice with the top players in the men's game.
While his covid-complaints around Novak Djokovic are well-documented, Kyrgios is also not the biggest fan of Nadal and even admitted he used to "hate and despise" the Spaniard.
"I couldn't stand him," Kyrgios told the Nothing Major podcast.
"I used to hate and despise him so much when I saw him walking around. He was one guy who always motivated me.
"If I played him I would get up for it and try and get the best tennis I could possibly play. I didn't feel that anger towards Federer or Novak when I played them.
"If I played Rafa, because everyone in our academies back home idolised him, they were like: 'he is such a hard worker, he's this and that.'
"I was like 'I can't stand this guy'. I wanted to show people you could just have fun and be chilled and beat people like that."
But even after Nadal has hung up his racket, Kyrgios is stil happy to poke fun at his former opponent and most recently suggested some of the Spanaird's mannerisms gave him the "ick."
Nadal has a reputation for being meticulous in his method to every shot, often running through a series of small actions before serving.
Kyrgios said that though gave him the "tennis ick."
"My tennis ick is when players take too long to serve between first and second serves," he told TNT Sports. "For example, Rafael Nadal."
Kyrgios, whose name is on the US Open entry list, did at least have some nice things to say about Roger Federer and Murray.
"Roger Federer, for me, was the hardest to play against," the 30-year-old said.
"Andy Murray was one of probably the best doubles players out of all four of them."
Kyrgios also had another thing in the world of tennis that he would like to alter and that was to see Wimbledon change its all-white dress code to all-black.
"At Wimbledon, It should be all black instead of all white. I think it would really pop on TV and I think it would be a good change up."