Former Australian number one Mark Philippoussis says Nick Kyrgios must focus on the here and now in order to rescue his career.
The 21-year-old will end 2016 at a career-high ranking of 13th, but the past year has been far from plain sailing.
Kyrgios won his first ATP 500 title at the Japan Open in October, but was given a three-week tournament ban barely a week later after giving up in Shanghai against Mischa Zverev.
The incident was not the first time Kyrgios has been accused of 'tanking' and Philippousis has become the latest onlooker to demand increased focus from his compatriot.
Philippoussis said: "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?'.
"There's no such thing as tomorrow. It's only today.
"I definitely can't support what happened and he knows that he screwed up too, but he had a hell of a year.
"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."
Jimmy Connors and John McEnroe have both offered to coach Kyrgios, who revealed he struggled to find motivation to play tennis after a listless elimination to eventual champion Andy Murray at Wimbledon this year.