In the past, questions were raised over the Scot’s fitness as he faded badly towards the end of five-set matches, particularly in his 2005 Wimbledon exit to David Nalbandian.

But with American coach Brad Murray now assisting him, Murray said: “It’s the first time I’ve made the final of a tournament, then won three matches the next week. That's obviously a good sign. I’ve won them all in straight sets, which has been good as well. I haven’t had too many long matches.”

He added: “At my age, I do need to get physically stronger. This is a first step. (I need to) get mentally stronger as well, not put mind over matter. I might be feeling a little bit tired on Friday, but I'm in the quarter-finals of a Masters Series for the first time with a good chance to make the semis.

“Regardless of how I’m feeling on Friday, I’m still going to go out there and give it my best shot.”

Murray, who now takes on Jarkko Nieminen in the last eight, gave an insight into Gilbert's impact on his general preparation, and admits he is finding it easier to spring out of bed than he used to.

“I love the American way of life. You get up at 6am in the morning, go downstairs. Normally in most countries, everyone will be looking sleepy. They’re all really happy to see you,” Murray said.

“I just prefer it a little bit more. It makes it easier for me to get up in the morning. I normally like my sleep. Here, I find it much easier to get up. I feel just a little bit more lively.

“I’m not getting up too early. I got up a little bit earlier today, but I have been sleeping quite a lot. But if I’m staying with Brad.... he was up at 2am this morning, which is actually ridiculous!”