Mark Philippoussis is convinced Nick Kyrgios can win the Australian Open - but his ringing endorsement comes with a word of warning.
Philippoussis believes Kyrgios's explosive firepower and rare shot-making could make the 21-year-old untouchable on Melbourne Park's hard courts this summer.
Speaking from experience, though, Philippoussis has also implored the tempestuous talent to realise youth is fleeting and not to waste his rich potential.
"You blink and he'll be 26 years old and all of a sudden he'll be kind of mid-20s or maybe 30 in the world and it'll be like 'what happened to him?'" Philippoussis told AAP on Thursday.
"There's no such thing as tomorrow. It's only today."
Philippoussis is disappointed that Kyrgios's late-season suspension for tanking at the Shanghai Masters has overshadowed the Australian's three-title year and rise to a career-high world No.13.
"Don't get me wrong, I definitely can't support what happened and he knows that he screwed up too, but he had a hell of a year," Philippoussis said.
"If I was coaching Nick, I would say what's very important is that you can't change who you are. Everyone is their own person and has their own personality.
"But at the same time I'd just tell him a couple of things about being aware of where he is and realising what he has and not taking that for granted.
"Just try and reach out to him because, truthfully, if there's one person that can relate to certain things that he's going through, it's me."
A dual Davis Cup winner, two-time grand slam finalist and former world No.8, Philippoussis nevertheless remains in many eyes - though not his - one of tennis's great underachievers.
Now 40, the Scud is keen to see Kyrgios cash in on his immense talent and urged the two-time grand slam quarter-finalist to aim high - and commit to becoming physically and mentally stronger.
"He has what it takes to win the Australian Open. It's as simple as that. He has the game," Philippoussis said.
"But he's got to believe that and he cannot go out and be happy with a quarter-final and just be satisfied."
Philippoussis said Kyrgios should draw inspiration from Andy Murray.
"It's inspiring. (Murray's) always been gifted and physically strong, but he's grown so much mentally and that's what Nick needs to do. He's got to toughen up mentally.
"That showed at Wimbledon, where he fell apart after he had that incredible first set against Murray."