Murray suffered a prolonged slump in form after losing to Federer in January's Australian Open final, and following defeat by Rafael Nadal in the Wimbledon semis he made a shock third-round exit at last month's US Open.
The Swede -- who beat Federer in an exhibition tournament in Abu Dhabi last week before losing in the final to Nadal, on whom he inflicted a shock defeat at last year's French Open -- was beaten in straight sets by American Robby Ginepri.