Andy Murray, the British No.1, admits that he "does not expect to win a grand slam next year", but is confident of a successful run at one of the majors should he stay free of injury.

The Scot is one of a group of youngsters - Novak Djokovic, Richard Gasquet and Tomas Berdych are others - tipped to challenge Roger Federer and Rafael Nadal's grip on the grand slams in the next few years.

Murray, 20, has never gone beyond the fourth round of a major, a stage he reached at Wimbledon and the US Open in 2006, as well as this year's Australian Open.

After moving into the top 10 in the world and successfully defending his San Jose title early in the season, a wrist injury sustained at the Hamburg Masters slowed the Scot's momentum. He was ruled out of the French Open and Wimbledon and looked short of his early season form when he exited the US Open at the third-round stage to Lee Hyung-Taik.

Now Murray, who has slipped from a career-high No.8 to No.21 in the ATP Tour entry rankings, insists there is more to come and hopes to embark on a successful run at one of the slams in 2008.

Speaking at the finals of the Road to Andy Murray programme, a junior tennis programme he helped to build and launch earlier this year, he said: "I want to try and focus on the positives' and, if I stay fit and healthy, I will have a good chance of a good run at one of the grand slams."

Asked if he had any targets for next year, he replied: "I don't know. I just want to keep improving. I am not expecting to win a major next year but I want to stay healthy the whole year. I have improved my game a lot since the start of this year. So I hope in a couple of years I'll be competing for the grand slams."

Despite being just 21, Nadal has already won three French Open titles, while Djokovic, 20, reached the semis at Roland Garros and Wimbledon as well as the US Open final.

Not surprisingly, Murray, who will represent Britain in the Davis Cup tie with Croatia at the weekend, insists there will still be one man to beat above all others: 12-time grand slam winner Roger Federer.

"He is still the top guy," said the Scot. "He has won three grand slams this year and made the final of the other, the French Open, so he definitely is still the guy to beat."