Roger Federer made a surprise withdrawal from the Barclays Championships Sunday with a lung infection.
But the world number one says doctors expect him to be cured in time to play the Indian Wells Masters from mid-March.
The world number one who has not played since beating Andy Murray for the Australian Open title, picked up the problem in recent days after returning to Switzerland after his Melbourne title, heading to Dubai and and then visiting a school his foundations fund in Ethiopia last week.
'I'm hoping to be back for Indian Well,s' said the 16-time Grand Slam winner. 'But of course there are no promises.
'This is something that with proper treatment will be finished,' said Federer, whose 2008 season was compromised by a case of glandular fever.
'I've been taking it easy, relaxing as much as possible. My breathing is a bit difficult and everything feels a bit slow. I can't take any chances until I'm fit again.
'It could be better, it could be worse.'
The Swiss player's place in the draw for the 500 series event which begins Monday was taken by Spaniard Tommy Robredo.
Federer missed Dubai in 2009 with injury and lost in the first round in 2008. He won the tournament in 2003-2005 and lost the 2006 final to Rafael Nadal.
Federer is due for further medical tests in several week to ascertain his condition. The Swiss said that the illness is much more straightforward than his glandular fever incident.
'I want to get back in shape and get back on court again. Once I'm back I'll be OK again.'
