The British number one, who has been confirmed as the new world number four, came away disappointed from his straight-sets loss to Roger Federer in the US Open men's singles final in New York on Monday night.

"It comes down to the tennis and I believe that there are so many things that I can improve on and work on and that's exciting for me," he said.

"I can still get better but that's something that in the past might not necessarily have been the case and for me that is a very good experience. It's a nice feeling to know that you can last."

The 21-year-old Scot was aware of the great strides he has made in 2008 with his physical fitness and mental strength.

"I think the most important thing for me over the whole two weeks was physically I was good, even against Nadal," Murray said.

His stamina and focus helped him reach the first grand slam final of his career over the last two weeks with epic victories over Michael Llodra, Jurgen Melzer, Juan Martin Del Potro and world number one Rafael Nadal, whom he beat in a rain-interrupted semi-final over Saturday and Sunday.

Murray added: "I had a long match with Del Potro as well and a lot of tough matches.

"Physically, for seven matches, I was pretty good.

"I know mentally now that I can get to a grand slam final, and physically. The only thing it comes down to is the tennis."