By Simon Cambers

NEW YORK (Reuters) - Andy Murray's hopes for a maiden grand slam at the U.S. Open may require him to beat world number one Roger Federer for a second time in five weeks after the duo were placed in the same half of the draw on Thursday.

Top seed Federer beat Murray last month to win his seventh Wimbledon crown and record 17th grand slam title but the Briton gained revenge when he crushed the Swiss master in the final of the Olympics at the All England Club on August 5.

Five-times U.S. Open champion Federer plays American Donald Young in the first round of the August 27-September 9 tournament in New York, while third seed Murray faces Alex Bogomolov Jr. of Russia.

Defending champion and second seed Novak Djokovic begins against Italy's Paolo Lorenzi and could face a semi-finals clash with fourth seed David Ferrer of Spain.

World number three Rafa Nadal, who has not competed since suffering a shock second-round Wimbledon defeat, withdrew from the U.S. Open with a nagging knee problem.

(Editing by Frank Pingue)