TENNIS - US Open Championships: So much has changed for Andy Murray this year, and so rapid has been his progress that the teenager's US Open fourth-round defeat at Flushing Meadows yesterday, completed with a flourish by Nikolay Davydenko 6-1, 5-7, 6-3, 6-0, was necessarily tinged with disappointment. Not that Murray would have any of that.

"Absolutely not disappointed at all. I had a great summer and could not have asked for more," he said. "My ranking is inside the top 20, I've beaten the best player in the world, and I've equalled my best result in a grand slam in my favourite tournament. I'm not going to walk away with any negative thoughts. This has been the best summer of my life."

There will be those, and his opponent was one of them, who may question why Brad Gilbert, who is being paid a small fortune by the Lawn Tennis Association to coach Murray, could not get him fired up at the start of yesterday's match, or when it resumed, having had the best part of a day to talk matters over.

"I had my chances on Tuesday, but he played just far too well at the start both days," Murray responded. "That's something that I have to learn from, and try and do things a bit different. But I've never played against someone who played a set as well as that."

Play began in warm sunshine, a rarity this year, with both men having caps pulled firmly down to cut out the glare. Clearly Murray, who by his own admission is never quite his best in the morning, needed to make the crispiest, cleanest of starts if he were to turn the match around after trailing by two sets to one when the rain interrupted play on Tuesday. However, three double faults in his opening service game, which he lost, were scarcely encouraging.

There had been a notable passivity about much of Murray's play in the opening three sets, his game plan against the world number six relying too much on Davydenko making mistakes, rather than Murray imposing himself. It was almost deferential.

The Russian, who will face Tommy Haas in the quarter-finals, was certainly surprised that Murray did not make more effort to take the initiative. "The way he played from the back of the court suited me fine."

There were any number of extended rallies in yesterday's culminating set, but it was only towards the end that Murray put some real beef into his shots, and then too often the ball flew long or wide. There is no doubting that he has the capacity to hit the ball with considerable whip and pace; one forehand service return screamed across the Louis Armstrong Stadium, leaving Davydenko rooted to the spot. The problem was that he was always under a little bit too much pressure to go for outright winners as much as he might have liked.

"It's tough playing someone that hits the ball so well on the run," he said. "You feel like you have to hit the ball down the middle to give him less angle. You need to serve well, and that was the one thing I could have done better."

Now that Murray has reached the top 20, and particularly with him having appointed the high-profile Gilbert as his coach, everybody has an opinion, and the majority of them are highly positive. "I love his game, and I think Brad has had an immediate influence," said Patrick McEnroe, brother of John, and the US Davis Cup captain. "Mopey Murray I called him back at the French Open and Wimbledon, just whining and moping. He still whines, but now he's sort of more positive. I really like his game. I think his potential is huge. He's shown that here."

Murray admitted that perhaps he did talk too much when he was on court, and that it was not good for his game. "It's something I spoke with Brad about. Maybe subconsciously it happens when I get nervous, or maybe I was tired. I really don't know why I was doing it but hopefully I'm going to stop."

It is all a learning process, and he will continue to have fluctuations of form, something that is only natural for a player of his age. He will now take a break and then return to prepare for Britain's Davis Cup tie against Ukraine this month in Odessa on clay. After that his eyes are set on the two remaining Masters Series events, both of them indoors in Madrid and Paris.

Guardian Service