John Newcombe says it’d be crazy to write off Nick Kyrgios as the big-stage showman resumes his audacious bid to become Wimbledon’s youngest men’s champion in almost 30 years.

“It’s a big reach, but his rise has been so meteoric so far that he doesn’t know – and we don’t know – where his limits are at the moment,” Newcombe told AAP ahead of Kyrgios’s fourth-round showdown with Richard Gasquet on Monday.

“Certainly the potential’s there and he’s certainly not afraid to grab the moments when they come.

“That’s a big plus for him.”

Not only does Kyrgios believe he can go all the way and join Newcombe, Pat Cash and Lleyton Hewitt as only the fourth Australian man in the professional era to lift trophy, the 20-year-old is vowing to deliver in style.

“I feel you should express yourself. You know, it’s a sport,” Kyrgios said of his flashy, sometimes abrasive, on-court conduct that has polarised fans and challenged officialdom.

The Canberra ace has an unabashed fan in three-time Wimbledon champion and former tennis superbrat John McEnroe.

“This guy is one of the greatest talents in a long time, bursting with personality. Reminds me of 35 years ago,” McEnroe told the BBC after watching Kyrgios’s breathtaking four-set second-round triumph over world No.8 Milos Raonic.

Newcombe is not as critical of the flamboyant youngster’s behaviour as some other tennis greats.

“He’s a free spirit out there and that’s how he performs at his best,” said Newcombe.

“I think he was having trouble for a set and a half playing against Milos because Milos gives you nothing.

“I had the feeling that Nick had to try to create some sort of flow to get into the match and in the end he did exceptionally well.

“The antics are a very small part of the whole package. If you look at the positive side of it, this kid’s got enormous talent.

“I think he’s only touching the edges of how good he can be.”

But the former world No.1 would like to see Kyrgios tone down the language.

“You can say things on court and you can leave out one or two of the swear words,” Newcombe said.

“You don’t need to have the swear words because if everyone went around doing that, it’d be a problem.

“So there’s a couple of things here and there that he doesn’t need to do and the rest is fine.”

Kyrgios will be meeting Gasquet for the first time since fighting off a grand slam-record nine match points and recovering from two sets to love down in the second round last year to topple the Frenchman.

The victory catapulted the Australian to stardom and he backed up to beat Rafael Nadal to make the last eight of a major for the first time.

After repeating the run at Melbourne Park, Kyrgios has a huge chance to make the quarter-finals once again in his quest to become the youngest men’s winner at the All England Club since Boris Becker in 1986.

And tennis’s great entertainer plans to do it his way.

“When I’m in that state of mind, when I feel relaxed and I’m playing around, I think that’s when I play my best tennis,” Kyrgios said.

“I’m focusing, but at the same time I’m having fun.”