Gap between Murray and the rest is growing, warns McEnroe

John McEnroe believes that Andy Murray needs to worry less about his physical issues and more about the problem of bridging the gap between himself and the world's best players.

"I don't know exactly what's going on with his back, but obviously one second it seemed like he was holding it and the next second he's sprinting," McEnroe said here yesterday in the wake of Murray's defeat by David Ferrer in the quarter-finals of the French Open on Wednesday evening.

"If anything, people are saying the gap is getting bigger, not smaller, so time is becoming of the essence. It almost seems like he's just got to get that mental part of it where he's got to forget about it. [He's got to say:] 'I don't care if my back is hurt, I'm not going to give it off.' It can work against some guys, I guess, but it's not going to work against the best guys. That's what he's got to think about if he's going to win Slams. These guys are tough to beat, really tough."

Although the defeat to Ferrer ended Murray's run of five successive Grand Slam tournaments in which he has reached the semi-finals or better, the suggestion of a growing gap between himself and the top three is misleading. On clay it has always been true that Murray has ground to make up – Rafael Nadal, Roger Federer and Novak Djokovic do have the advantage of playing on a surface on which they grew up – but the true test of Murray's Grand Slam credentials will come in the next three months on grass at Wimbledon and on hard courts at the US Open. The evidence of the year so far – most notably the Australian Open, where Murray went even closer to beating Djokovic in the semi-finals than Nadal did in the final – suggests that the Scot remains within touching distance of his greatest rivals away from clay.

For the next two months – beginning with next week's Aegon Championships at Queen's Club and ending with the Olympic tournament at the All England Club – the focus will be on grass. Wimbledon starts in just 17 days' time and Murray, who returned home yesterday, is planning his first practice session on grass tomorrow in the build-up to Queen's.

The rest of the summer should also give a guide to the long-term prospects for Murray's collaboration with his coach, Ivan Lendl, who will be with him throughout the grass-court season. "The more time we spend with each other the better he will understand my game and the better he will understand me as a person," Murray said. "I will know the right questions to ask him before big matches, big tournaments. I'm still learning a lot from him and hopefully that will be the case leading up to Wimbledon."

He added: "A lot of the messages are the same for all of the surfaces. What we were discussing pre-Australia and pre-French are pretty similar. We did some different practices depending on the surfaces, like I always do, but it will be good to have him there for the whole build-up."

McEnroe believes that Lendl will be driving home to Murray the importance of remaining focused on his tennis. "I'm sure he didn't get hired to get berated like the other coaches were," McEnroe said. "I'm guessing he doesn't quite know how to answer this, because he seemingly used to fire coaches while the match was going on. Lendl is sitting there and he's obviously said, as most people would agree: 'It's probably not the best idea to get negative. That's what's costing you. You're wasting too much energy to beat the best guys'."