The chatter among those who spend hours training their cameras on tennis players is that Rafael Nadal has lost a bit of weight and muscle since the All England Championships. That might serve to give the rest of the men's field at Flushing Meadows hope because the Spaniard offers every impression of being supremely grooved to become the first man since Rod Laver in 1969 to win the French Open, Wimbledon and the US Open in the same year.

Andy Murray also looks a touch leaner than during those halcyon Centre Court days of early summer. His mood is every bit as casual as it was at SW19. He is inclined to break into a wide smile when you least expect it and when he does so, it alters the entire complexion of his character.

He was wreathed in them four years ago when he lifted the US boys' title and was escorted with Judy, his mother, to the top tier of the Arthur Ashe Stadium where the images were of a young man who was well on his way to reaching for the skies. The interim period has not been without its moments of turbulence, but back then Murray had his sights set on becoming a top-ten player and having achieved that on the back of his finest performance in a grand-slam tournament - reaching the Wimbledon quarter-finals - and winning his first title in a Masters Series event within the past seven weeks, he is ratcheting up his levels of ambition.

“Wimbledon was clearly a turning point because what had become a good season for me now has the potential to become a great one,” Murray said. “My target this year was to qualify for Shanghai [the top eight players of the year compete for the Tennis Masters Cup in November] and that has become a very realistic prospect. The next one after that is to win a grand slam. I don't think you know if you are ready to win a tournament like this one - you just have to do the things you have to do to give yourself the best shot. If the opportunity comes, you either take it, or you don't.

“I would like to think that I will take that opportunity when [notice the when and not if] it comes, but I've not been beyond the quarter-finals of one of these tournaments. I'm putting in all the work on and off court, I feel I can do it physically and so it will come down to putting my game together consistently over two weeks.”

When Murray agreed to have a chat yesterday, it was on the premise that he was not asked about the Olympic Games, where his first-round defeat to Lu Yen Hsun, of Taiwan, was one of those shattering episodes that happen from time to time. What that setback did allow Murray was a little more breathing space after the Games which, as brilliant as they undoubtedly were, served as yet another debilitating drain on mind and body, especially if one's medal hopes were dashed at the start.

From the North American hard-court circuit, to Beijing and back, takes an awful lot out of people, even those at the front of the plane. The US Open, which starts today, has long been the survival of the fittest and those who can keep their head amid the chaotic tumult of much of what goes on in the name of grand-slam tennis, will come out on the other side. A year ago here, Murray's wrist was bothering him, he stayed in the same hotel as Brad Gilbert, his erstwhile coach, to try to keep the peace and no one was overly surprised when he was beaten in the third round by Lee Hyung Taik, of South Korea.

This time around, with the intensity of the Gilbert partnership replaced by the “keep it light, keep it upbeat” Team Murray that, with his personal press attaché here, numbers seven, everyone is walking around with a ready smile. “Every new relationship takes time to settle down,” Murray said. “Though I didn't have a particularly good spell immediately after Dubai [in March, in fact he didn't win three matches in a single tournament until Wimbledon] and was constantly being asked about what I was doing having this team around me, it was something I always felt was going to be the best for me in the long term.

“I knew I would enjoy playing and travelling much more, it was a new experience for all of us but they have been a massive factor in why I'm playing much better this year. Each time I have made a decision on my coaches, the period immediately after it has been tough but it worked out in the end. All the decisions have been hard, especially having to tell Mark Petchey that we should part, but my ranking has gone up steadily over the last few years and every change has been of benefit for me.

“I have set myself lots of goals. Last year, to become a top-ten player was huge for me, but it does not matter so much now. The players I have beaten, my record against the top players, bar Nadal, those are the things that matter. I would rather go into a slam ranked No12 in the world but with the best players thinking I have a shot at winning, rather than be No5 or No6 and not be given much of a hope.”

In the first round, Sergio Roitman, of Argentina, who lost at this stage last year in his only appearance in the main draw, should not pose too much of a threat in a match scheduled for today, but Murray speaks about being on his guard and his game right away. There is no room for the early laxity that characterised many of the performances at the outset of his professional career.

A semi-final against Nadal is the juiciest of prospects. This is New York - a lot of beers will have been downed in the stands, a lot of planes will have flown from nearby La Guardia airport, a lot of hype will have been expended, but Murray senses he is ready. And that is what matters.