MARCH 21 2008 22:23h
Haas produced an impressive run this week having knocked out Andy Roddick and Andy Murray.
World number one Roger Federer reached the last four of the Pacific Life Open without hitting a shot on Friday when his quarter-final opponent German Tommy Haas pulled out with a sinus infection.
Swiss Federer, three times champion at Indian Wells and seeking his first ATP title of the year, will next meet seventh seed David Nalbandian of Argentina or American Mardy Fish, who were playing later on Friday.
"I deeply regret that I have to withdraw," Haas said in a statement. "I was playing my best tennis of the season and was looking forward to playing Roger this afternoon.
"I am sure the tennis will be incredible this weekend and I look forward to returning again next year."
The 29-year-old, a former world number two whose career has been dogged by a series of injuries, produced an impressive run this week, knocking out sixth-seeded American Andy Roddick and Britain's number 11 seed Andy Murray.
Top seed Federer, who has beaten Haas eight times in 10 career meetings, said: "I am very sorry for Tommy as I was looking forward to another great match with him.
"We have played quite a few times and I know and respect Tommy a lot. I hope he gets better quickly."
Saturday's remaining semi-final will be between holder Rafael Nadal of Spain, who is seeded second, and third-seeded Australian Open champion Novak Djokovic of Serbia.