"I think you have to trust yourself that when you are tested, you're going to play better tennis," said Murray.
"You never know for sure, but in the buildup to the tournament I played very well.
"I haven't lost a set here yet, so maybe I'm expecting to play too well or whatever. But I've done a good job so far in this tournament. I can't be disappointed with where my game's at."
Murray has never beaten Federer in a Grand Slam.