"When you work hard for something for a lot of years, you know, it's going to take a bit of time to really fire yourself up and get yourself training 110%," he said. "That's something that I think is kind of natural after what happened at Wimbledon."
Murray added that he still made a full effort to defend his U.S. Open title. "I mean, I have been here nearly three weeks now," he said. "I practiced a lot, and played quite a lot of matches, as well. So I gave myself a chance to do well because I prepared properly."
The Scot has won two Grand Slam titles in the last 12 months, as well as the Olympic gold medal last July. "If someone told me before the U.S. Open last year... I would have taken that 100%," he said, but acknowledged that it has also been draining.