Murray has pulled out of another tournament as he battles back to fitness and form after a year out, and his chances of being ready for Wimbledon are hanging by a thread.
The former world No1 is aiming to make his comeback, after hip surgery in January, at the Fever Tree Championships at Queen’s starting on June 18, or as a last-ditch effort at Eastbourne the week before Wimbledon.
McEnroe took six months off from the pressures of tennis in 1985, aged 27, but failed to add to his seven Grand Slam titles.
And last night he said: “I carried on for about seven years after that, a long time. You keep giving yourself reasons why it’s worth it, the upside.
“It’s worth taking semi-humiliation. You’re still out there doing something you love. You’re not as good as you were – I’m not saying Murray won’t be as good as he was – but it will be tough to come back and be better than he was when you have hip surgery. Maybe they can cure it completely, but that’s a pretty tough injury to overcome.
“When I took my time off I didn’t do it so I would be worse when I came back. My plan was to be better.
“It’s tough. You sink to a certain level where you can’t take it any more. I felt like I was still one of the top ten guys but to even keep that ranking, I had to do a lot more than I was capable of in terms of travel with kids and family.
“Murray seems like the type who is doing everything he possibly can to get back to what he was. There’s no question that he’s coming back to win majors.
“Can Murray come back without a warm-up event? Yes. Roger Federer did that in 2007 and 2009. But I’m sure he would be realistic. It would be tough to go a long way in the tournament if he hasn’t played.
“When you have a hip problem you have a tendency to be more cautious. I had hip issues, and I felt like I lost speed. It’s not a good feeling, particularly when guys are hitting it harder than ever. If you are not feeling right it can be tough. There is no way to know if you are 100 per cent.
“We all know how different practice is to a match on the Centre Court at Wimbledon. It’s a year – that’s a long time.
“We don’t have to dig too deep to find guys that are having trouble. You go from the extreme of Roger being able to pull it off to Stan Wawrinka, who has barely played. Novak Djokovic doesn’t seem like himself yet and that’s been a couple of years.”
McEnroe, who will be a BBC pundit during Wimbledon, believes Djokovic’s problems – he was knocked out of Roland Garros on Tuesday night in one of the biggest upsets so far by the world No72 Marco Cecchinato having started to find form following elbow surgery – are chiefly in the mind.
“It’s more mental with Novak,” he said. “In some of the longer rallies it looked like he didn’t have the same endurance. He should have reached the semis. He should have beaten this guy.”