Federer's time out should boost Murray chance.

ROGER Federer has been forced to withdraw from the Dubai Championships starting today because of a lung infection, 'I can't play, it's too risky,' Federer said. '(It is) a lung infection. It's the first time I've had it. The breathing was difficult. I'm still very tired and a bit slow with everything.' He aims to return to competition at the World Tour Masters tournament in Indian Wells starting on March 11, but said he would not take any chances after glandular fever disrupted his preparations for the 2008 season. [ABSTRACT FROM PUBLISHER]