Speaking at a Telstra event, the eight-time Grand Slam champion gave his opinion of the wayward talent.

"I find him a fascinating talent and a fascinating person in a sense that he's still young and pretty clear on his feelings about that game, and he has a openness to really speak it," Agassi said.

"We both have some strong rebellions. I'm not sure for what reasons his are but he also seems pretty clear of his rebellion.

"For me, I was confused by my rebellion. My guess from the outside is he has the luxury of knowing himself a bit better than I did, so hopefully we'll see from the outside a career of something changing in front of our eyes for the better and growing up.

"We all have to grow up but we never stop learning so I don't say that condescendingly, I say it honestly."

And despite a colourful career that saw him almost give the game away several times, Agassi stopped short of offering Kyrgios advice.

"You can try to give advice for him to overcome the demons or the perspectives but I think that's not healthy for him in the long run," he said.

"I think he needs to come to terms with what he wants from himself, what he wants for himself and tennis is an innocent bystander in that dilemma.

"Hopefully he'll find good reason and good success in his life on a daily basis, whether that means tennis or not.

You have to come to terms with who you are and find where tennis plays a part in that."

Agassi said he believed Kyrgios had the talent to become No.1, but first had to master the ebbs of professional tennis.

"From a talent perspective, absolutely.

"But you have to solve the rollercoaster of it because you don’t reach number one with peaks and valleys. You have to balance it out.

"You can win grand slams and go to heaven for two weeks but really, being No.1 requires sustainable effort that doesn't allow for that kind of tumultuous ride."