Andy Murray cannot please everyone, it seems. Yesterday, he made his first public appearance since his astonishing run to the US Open final and though he was greeted by a sea of excited young faces at a sports centre in South West London, some of the youngsters proved harder to impress than others.

"One of them told me that I needed to smile more, which was good," said Murray, who (cheerfully) spent yesterday morning greeting competition winners at a David Lloyd Leisure Centre in Raynes Park.

"I just kind of enjoy being around kids, playing with them and hopefully giving them a bit of extra motivation. The kids have been really good fun and it kind of brings you back down to earth when they're just saying whatever they feel."

Murray does not seem to need much bringing down to earth, mind you, despite his achievements in New York and the fact that he is now No.4 in the world and a close acknowledged rival to Roger Federer, Rafael Nadal (whom he beat in the semi-finals at Flushing Meadows) and Novak Djokovic. He has already spoken to his fitness advisors about how to increase his workload during the off-season in December, which he will spend training in Florida, and is planning to spend the remaining weeks of competition developing areas of his game ahead of another big push forward next year. The Australian Open, the first grand slam of 2009, is still four months away but Murray has already set his sights on doing well there.

"I think it gives you extra motivation when you get that close in a slam," he said. "Even though I got beaten pretty comfortably in the final by Federer, you're motivated because you've got that far. But also you understand that you need to work a lot on your game, get fitter, get stronger."

Before Murray can concentrate on further putting the wind up Federer, Nadal and Djokovic, he must first turn his attention to this weekend's Davis Cup World Group play-off tie against Austria at Wimbledon, when he and his brother Jamie will be joined in the team by second singles player Alex Bogdanovic and Englishman Ross Hutchins. Murray has already begun practising on grass and though he admitted yesterday to some discomfort in his right knee, which often suffers when he switches between surfaces, he appears to be committed to playing on all three days if necessary. He knows that the team needs him to perform if it has any chance of beating Austria and retaining its place in the top division.

Murray has said consistently that he loves playing Davis Cup and would surely not be bothering unless he thought his team had a chance of doing something other than perpetually struggling against relegation. "I do think we do have a chance of doing very well in Davis Cup and I think a lot of it comes down to the draw," said Murray. "If we get home ties we can put it on a surface that the other team doesn't like."

Murray would have preferred to play the Austrians on an indoor court rather than grass, but he understands that team captain John Lloyd has the final say. It is unlikely to stop him saying what he thinks, though, for he has always been a forthright personality. No wonder he does not mind it when his younger fans prove to be equally forward.