But winning grand slam titles is about peaking when you need to and today he will look to do just that when he takes on Jo-Wilfried Tsonga for a place in the quarter-finals.
Having won nine out of 11 matches with Tsonga, Murray should take plenty of confidence into today's meeting, despite squandering a winning position when they met in Canada a couple of weeks ago.
"I've had a lot of close matches with him and I've won a lot against him so I would say my game matches up well," said Murray. "But he's obviously playing extremely well just now and I'm aware it's going to be a very tricky match."
Murray led Tsonga 3-0 in the final set of their Toronto Masters quarter-final only to lose it, with the Frenchman going on to win the title.
"I played a good match," said the Scot. "I was up a break in the third set and didn't manage to close it out. Obviously if I get myself in that position again, hopefully I'll do a better job of that. But I don't need to change too much."
The lapses in concentration have been a feature of Murray's performances at times this year, albeit that is a criticism which he feels is a little harsh. "Sometimes guys can start playing well [but] often people don't like to give credit when a guy is playing some good tennis as well," he said.
"Over the course of a two or three-hour match there are going to be ups and downs. You just need to hit the reset buttons as quickly as possible so it doesn't last for two or three games.
"Sometimes it can be [that you are] struggling to stay ahead or sort of having ups and downs in matches, but you're going to go through that in an 800, 900-match career. You've just got to keep doing the right things, keep going for your shots, keep making good decisions - that's all you can do, really."
Former US Open finalist Greg Rusedski, who is working at the tournament as a television pundit, questioned whether Murray is in good enough shape to go much further at Flushing Meadows. However, the Scot is adamant that he is fully fit after the concern of round one against Robin Haase, when he scrambled through in four sets despite suffering cramps.
After the disappointment of his quarter-final loss at Wimbledon, the two-time grand slam champion stepped up his fitness regime with a vigorous training camp in Florida.
He certainly looks in good shape and, with a potential quarter-final against Novak Djokovic to come, Murray will be keen not to get embroiled in an epic five-set battle today. "If you feel good physically anything can happen so you just need to be ready each match now and I'll hopefully play some good tennis," he said.
In his third-round win over Andrey Kuznetsov, Murray was noticeably grabbing his thigh and lower back at times as the Russian forced the match into a fourth set. However, Boris Becker, taking a bit of time out from his job as coach of Djokovic, said that may have been Murray's way of dealing with stress.
"He played well and moved well in the fourth set and the match wasn't too long," Becker said. "Two hours, 35 minutes isn't really testing your body much. If he has a nice evening off and a soft practice he can get ready for a tough match against Tsonga."
Murray has not beaten a top-10 player since he defeated Djokovic in last year's Wimbledon final but said it was not a statistic that costs him any sleep. "I just try to win the match, that's basically the goal," he said, perhaps protesting a little too much.
"It's not really about how you play because sometimes you can play really good tennis and lose - I'm more interested in trying to win the match against Jo, playing the right tactics to give myself the best chance."
Yesterday, he looked happy enough even as he practised in the heat of a brutally humid day, under the close watch of coach Amelie Mauresmo. The Frenchwoman has fitted into Team Murray well and the eighth seed's relaxed preparation, which included going to watch some golf and basketball, was her idea.
"It hasn't changed anyone's personality or how we behave but it has changed things in terms of how we communicate," Murray said, when asked to compare his relationship with the former women's world No.1 to the one he shared with his previous coach, Ivan Lendl.
"I have said that it is much easier to communicate with her and that is a positive."