Novak Djokovic and Andy Murray have shared a rivalry for 20 years and have known the pain and sacrifice of their calling for many of those, as well, so the Serb speaks from the heart when he tells the Scot to beware the hidden dangers of grass when he returns at Queen’s on Tuesday.

Djokovic thinks Murray is well advised to make his comeback on the surface he loves most, where he has won five times in front of a home audience, but warns that he needs to take care in his tricky engagement against Nick Kyrgios in the first round of the Fever-Tree Championships.

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Murray is nursing his hip back to good health after surgery in January, and Djokovic has his serving elbow to care for, after a shock exit in the quarter-finals of the French Open two weeks ago.

In the lead-up to his opening match against the Australian qualifier John Millman, Djokovic said: “The one thing – again, I don’t know the state of his hips – that could be a bit dangerous is slipping on the grass. That’s something that is very unpredictable and grass is always this kind of surface where one wrong footing can make something go wrong, especially in the hips. I just hope for his sake that doesn’t happen.”

Both men were eliminated on day nine of Wimbledon last year, suffering spiritually and physically, although Djokovic is ahead of Murray in the remodelling of his game. He believes the biggest challenge facing both of them after being at or near the top of their sport for so long will be mental more than physical. Facing opponents they once beat regularly would be, “circumstances that are quite new, because we’ve had tremendous success a couple of years ago, and for a period of five, six years alongside Nadal and Federer”.

He said: “I’ve known him since we were 11, 12 years old. I’ve always had a wonderful relationship with Andy, never experienced anything negative in that relationship. We still are big rivals on the court [because] we’ve had so many great matches. But he deserves a chance – everybody deserves a chance – to come back. Coming back after a major injury is also something that inspires you, brings you that motivation. You breathe in a new breath of life. You feel like you have restarted your career. I’m sure that he’s more motivated than ever to go out there.”

For most of his career, Murray has ground opponents into the dirt, grass, submission or to the point of distraction. However, the Scot suspects he might have to fine-tune his attritional strategy if he is to compete at the highest level again, and look after his body.

Murray, who has idled and fretted for 11 months trying to fix a left hip injury that has plagued him for at least eight years, returns in hope as much as expectation.

And the man his former trainer, Jez Green, calls “the Problem Solver”will need all his considerable acumen to, firstly, give Kyrgios a game after the Australian’s stellar three-set effort against Federer in the semi-finals in Stuttgart on Saturday, and, second, have at least a half-way chance of competing, unseeded, at Wimbledon, which starts on 2 July.

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“I’ll see when I start competing again, what works and what doesn’t,” he said. “It’s sort of getting the balance between playing a style that is effective and can win you matches, I could on Tuesday go and serve-volley every single point, which maybe might be better for my body, but is unlikely to win me lots of matches at this level. It’s trying to find the balance between playing a style that wins you matches and preserving your body as much as you can.”

Cameron Norrie, the British No 2, who will come up against the three-time slam champion Stan Wawrinka in the first round, played two sets against Murray on Friday. “I played flat out,” Norrie said. “We organised it like a proper match. We went at it. It was a good level. There was no mercy.

“No, I think he’s playing well. Obviously he hasn’t played many matches, so there were a couple of points here and there where he wasn’t quite on it. But he’s hitting the ball well and he’s moving great. Everyone’s pretty pleased to have him back. He’s a great role model for British tennis. It’s great to have him back and I wish him the best of luck for this week.”