The Scot had spoken of his delight at being back at the All England Club after two memorable victories but his mood was very different following a 6-4 6-2 6-2 loss to Denis Shapovalov in the third round.
Murray has struggled with a succession of niggles since his hip resurfacing surgery in 2019, the latest a groin problem that has severely limited his practice opportunities.
That left the 34-year-old to ponder whether it was worth all the hard work needed simply to get back onto the match court if he is not able to produce the tennis he needs to.
Speaking on BBC One, McEnroe said: “It just really depends on can the body take it. I’m not a doctor but he’s got a metal hip, you’re 34, there’s a lot of wear and tear on that body. We want to see him go out on the terms he wants to go out on. Ultimately, you have to get on the court.
“He’s going to go to a cement surface now, that can’t be easier on your body. He’s the type of guy, he needs to play a lot. Obviously his body wasn’t up to it against Shapovalov. The guy was hitting the ball so big. There’s a fair amount of guys that hit the ball as hard as that.
“The most important step in tennis is the first one. You need explosion. If you don’t have that, you’re done. Murray is in the top six to eight movers ever for me. That way of playing is extremely difficult to do when you feel deep down you’ve lost something.”
Time will tell whether it was Murray’s disappointment talking, but there is no doubt his comeback will only be sustainable if he can maintain a level of fitness that allows him to train consistently.
Next up for Murray is a fourth Olympic Games in Tokyo where he will play singles – a third successive gold medal looks well beyond him currently – and doubles with Joe Salisbury.