With his big smile and boyband looks, Jack Draper has quickly become a massive fan favourite at the US Open. But the dashing young Englishman in New York has not been not enjoying a rock-and-roll lifestyle on his way back to the fourth round of the US Open.

Instead, Draper is straight back to his Manhattan hotel every night to drink tea and watch his TV rather than throw it out of the window. Even the drug caffeine is banned. He is not exactly Keith Richards.

But there is method in his lack of madness as the 22-year-old’s young career has been dogged by injury and fitness issues. And with a great chance to reach his first Grand Slam quarter-final against world No.39 Tomas Machac on Monday, the British No.1 is happy to make “many sacrifices” at night so he is ready for the day job.

“I always was someone who liked to enjoy myself and maybe didn't have a working mindset,” he said.

“Since last year, I've definitely sort of put my head down a lot more and just focused on myself and what's important to me and becoming a top player.

“Now it's more important for me to go back and just have a Deliveroo in my hotel, so I'm taking full advantage of any recovery to be able to give my best on the court.

“I try and watch movies. I can make a cup of tea in the room and then watch a series or something. I watched Gangs of London recently. Just anything to conserve mental and physical energy, whether that's calling home or just being chilled, really.

“It's sometimes a bit of a lonely existence being a top tennis player. You have just got to make many sacrifices.”

Draper has even changed his pre-match coffee order under instructions from his coach James Trotmann. “My coach doesn’t want me taking too much caffeine,” he laughed. “It sends me too far over. For now, it is de-caf cappuccino.”

This Grand Slam, though, is a chance for all the hard work to pay off with Carlos Alcaraz and Novak Djokovic already out.

If he beats Machac, he would face the winner of the Aussie derby between Alex de Minaur - who knocked out Dan Evans - and Jordan Thompson in the last eight.

But the dangerous Machac beat Draper in Geneva in May - and the Czech also overcame Djokovic in the semi-final. Yet Draper, who has reached the last 16 without dropping a set and losing his serve only once, insisted: “I feel like I can play better. Hopefully I can keep going.”