It has been a fairly typical last two months for Nick Kyrgios. The 20-year-old Australian has beaten Roger Federer, played one of the shots of the year with a winning through-the-legs lob against Andy Murray at the French Open and talked about avoiding all tennis for a week, less than a fortnight before Wimbledon, after finding it “difficult to get myself engaged” when losing at Queen’s Club last week.

To cap it all, the world No 29 will start Wimbledon next week without a coach after sacking his fellow Australian Todd Larkham, who had been working closely with him since last summer.

Whether Kyrgios is blasting cannonball serves, hitting outrageous shots, sporting his latest sharp haircut or tattoo or dazzling your eyes with kit as colourful as his on-court language,it is all but impossible to ignore the young man from Canberra, who was singled out this week by John McEnroe as the most likely future champion from his generation.

The American likes Kyrgios’s “belief and intensity” and believes he is a character who can spread the appeal of tennis to a younger audience. “If he takes it seriously and is able to commit himself he is going to be a truly great player,” McEnroe said.

With Kyrgios, nevertheless, you sense that his tennis future might be in the balance. He has all the talent but does he have the passion for the sport? He has had a stunning year since making his breakthrough last summer at Wimbledon, when as the world No 144 he knocked out the then world