The former tennis ace liked getting the chance to assess his game on court against the Big Three but explained how he found it hard to be "friends" with them as they competed for Grand Slam glory.

Speaking on snooker legend Stephen Hendry's Cue Tips YouTube show, Murray said: "I would practice with them, I'd practice with Djokovic and Nadal.

"When I first started, I would practice with Federer. But after a year or two, he stopped, he wouldn't practice with me anymore. He never practiced with Djokovic or Nadal, I think because he considered them to be a competitor.

"I liked practicing with them just because it gave me the chance to see where my game was at. I wouldn't practice with them a couple of days before a big match, but a couple of weeks out from a major tournament, then I would practice with those guys."

Murray explained that he found it hard to socialise with his rivals during his playing days but is willing to spend time with them now after bringing his career to an end last year.

The three-time major winner said: "I was never going for dinner with them. Whereas now I'd love to do that, see them a few times socially.

"Generally, if I'm socialsing with friends and family, you want to feel like you can tell them if you're struggling with something. But if you're competing against them, you wouldn't do it."

Murray did coach Djokovic for a six-month period that ended earlier this year and explained that he "didn't get the results" he wanted from the partnership.

The former world number one told The Tennis Podcast earlier this month: "You're working with not only one of the best tennis players but one of the best athletes of all time, so my expectation was that it was going to be extremely challenging.

"Novak, like myself, is a challenging character in terms of the way he goes about his tennis, (it) is extremely demanding.

"I look back on it and I'm glad that I did it. It's an amazing experience that I've had."