The hits keep coming for Nick Kyrgios, with Australia’s greatest-ever tennis player lamenting the 20-year-old’s “ugly” behaviour at Wimbledon.

The legendary Rod Laver, the only player in history to complete two calendar-year grand slam sweeps, says Kyrgios needs to “just let his racquet do the talking and win matches”.

While Laver rates Kyrgios’s game and believes he has the potential to be a “tremendous asset”, he believes the two-time grand slam quarter-finalist’s on-court conduct is holding him back.

“Nick’s young and maybe doesn’t realise what he is doing sometimes. He’s playing with emotion. A crowd builds him up,” Laver told ESPN.

“That’s certainly something that he needs to grow out of and he needs to grow out of that sooner rather than later as his performance here, I don’t think many Australians would agree with it.

“There’s certainly no excuse for swearing. That’s just bad behaviour, that’s ugly.

“I have spoken to John Newcombe and Fred Stolle and Tony Roche and people who are closer to him, and none of them agree (with his antics).

“They would like to see him stop doing that and just let his racquet do the talking and win matches.”

Laver, who was in the Royal Box for Friday’s semi-finals at the All England Club, hopes Kyrgios doesn’t live to regret his actions.

“Maybe, in 10 years from now, he will look back and think, ‘Maybe I shouldn’t have been like that and shouldn’t have acted that way’,” he said.

“It’s a shame that people are talking about this rather than about his tennis. Nick’s a great player, he has proved that the last couple of years now and he is capable of being a tremendous asset.

“We would love to have another champion in Australia. We’re losing Lleyton Hewitt, who is the epitome of sportsmanship and trying hard. We would like Kyrgios to take that role.”