Nick Kyrgios of Australia sleeps during a changeover against Andy Murray of Great Britain (not pictured) on day two of the 2015 US Open at USTA Billie Jean King National Tennis Center. PICTURE: USA TODAY Sports

By Mike Hytner/The Guardian

Shane Warne has weighed in on the behaviour of wayward tennis star Nick Kyrgios, imploring the 20-year-old not to ‘waste his talent’ and to remember that ‘respect is way more important than being liked.’
In a letter addressed directly to Kyrgios after his US Open first-round defeat to Andy Murray, and posted on Warne’s official Facebook page, the former cricket great took Kyrgios to task for “testing our patience”, telling him it was time to “step up and start winning, no excuses”.
Warne, no stranger himself to controversy as a youngster, wrote:
Dear Nick Kyrgios,
We all realise you’re only 20 & have a lot to learn buddy. But please don’t waste your talent, everyone in the world, especially us Australians want to respect u. Remember respect is way more important than being liked, u need to respect the game of tennis & yourself. We all make mistakes, but it’s how we learn from them & the way we conduct ourselves when we lose that shows true character. You’re testing our patience mate, show us what you’re made of & how hungry you are to be the best in the world, it’s time to step up & start winning, no excuses. No shame in losing, but show us you will never give up, that you will give it everything to be the best you can be, respect is earned not given ! I believe in you & know you can do it, but now’s the time my friend...
Kyrgios burst into the consciousness of the tennis world with a run to the quarter-finals at last year’s Wimbledon, where as a wildcard he defeated Richard Gasquet and then world No 1 Rafael Nadal.
Despite another grand slam quarter-final appearance, at the 2015 Australian Open, that remains his career highlight and he has endured a tough year since reaching the last eight in Melbourne.
He parted ways with his coach ahead of Wimbledon – where he was forced to deny accusations of insulting an umpire and throwing a game at separate stages of the tournament – and he became embroiled in the Bernard Tomic affair with Tennis Australia before suffering a dip in form culminating in him being overlooked for a crucial Davis Cup rubber.
Kyrgios was dealt a tough draw when paired with Britain’s world No3 Murray in his opening match at Flushing Meadows, and the meeting went as expected with Murray winning in four sets.
During the evening session encounter, Kyrgios showed glimpses of his undoubted talent with a string of impressive groundstrokes, but came in for criticism afterwards for some of his in-play decisions – and his continued antics on the court.
John McEnroe, the original superbrat of tennis, labelled the Canberra player’s shot selection “boneheaded” and accused him of thinking he was some kind of “vaudeville entertainer” instead of concentrating on winning points.
Kyrgios’s dark side came to the surface when he slammed his racket into the ground several times in frustration and later received a warning for an audible obscenity.
He also complained to the chair umpire, Carlos Ramos, that fans were being allowed to move around mid-game. “Middle of the game. Unreal. Such bullshit. Fucking bullshit,” he fumed.
In between games, he bemused onlookers on a few occasions by reclining in his chair and closing his eyes, apparently on the verge of falling asleep. He later told reporters that he was “just taking a nap, I guess”.
But when focusing on his game, Kyrgios did give a decent enough account of himself, showing a determination that has been lacking recently by refusing to give up at two sets to love down and battling back to win the third set.
After the match, Kyrgios indicated he was pleased to move on from the incident which outraged the tennis world two weeks ago, when he delivered a crude sledge to Stan Wawrinka in Montreal and was subsequently hit with a fine and ban by the ATP.
“I thought I’ve been dealing with that pretty well. Obviously it’s been tough. But I think I’ve moved on from it,” he told reporters afterwards.
“I’d like to think that I’m going to learn from it. I think I have. I think I’m on the right path. I don’t think any of us in this room right now were perfect at 20.”
Warne is widely considered to be one of the greatest bowlers in cricket history, although like Kyrgios he too divided opinion and had a knack for attracting negative headlines during a controversial playing career.
The spinner was fined for providing information to an Indian bookmaker in 1994 and again for a verbal attack on Sri Lanka captain Arjuna Ranatunga in 1999, an incident for which he was also banned.
In 2003, he was sent home from the Cricket World Cup after testing positive for a banned substance and was handed a 12-month ban from the game and in 2013 he was again fined and suspended for his role in an on-field exchange during a Big Bash League match.
Warne’s colourful love life has also been a regular feature in tabloid newspapers throughout and beyond his cricket career.