Beijing - China Open champion Serena Williams spoke of her frustration at
withdrawing early from a second consecutive tournament on Friday, but said
it was too early to say if her season was over.
The top seed in
Beijing withdrew from the $5.4 million tournament ahead of her
quarter-final match because of a left knee injury.
number one was due to play Australian Samantha Stosur after winning her
third round match on Thursday evening with a bandaged knee.
power-hitting American is scheduled later this month to play in the WTA
Finals in Singapore, the end-of-season finale involving the world's top
eight women players.
But she refused to say if her participation in that event would be affected by her injury at a press conference in Beijing.
don't know yet. I haven't had time to get an MRI scan. I'm going to do
all that and see what is the root of the problem, I think," she said.
would have secured the year-end number one ranking if she had retained
her title at the final in Beijing Sunday - the fourth time in her career
that she has achieved such a feat.
She is also a four-time winner
of the end of season finale, and the current champion after defeating
recently-retired Chinese star Li Na in last year's final.
feel this way for Singapore, I don't think it's smart for me to play.
Other than that, I'm just going to see how it goes," she told reporters on
Williams made it through to the quarters in Beijing after a
scare in a back-and-forth game against Czech player Lucie Safarova that
she eventually won 6-1, 1-6, 6-2.
Stosur, the 2011 US Open winner and former world number four, will now go straight into the semi-finals.
Williams had to be helped from the court as she retired ill during her first set at the inaugural Wuhan Open in China last week.
She said it was "especially" frustrating to withdraw from the China Open.
really frustrating, especially from here. This is a really big
tournament for me. I'm defending champ," the 33-year-old said.
as a defending champ, you always want to do your best to defend your
title. That's why I played yesterday. I've got to at least give it a
chance. I've done well here. This is my title.
"So more than
anything, it's extremely frustrating. You know, I wanted to be here. To
come all this way and not to take the title, it's just a waste."
Her sister Venus, the 16th seed in Beijing, withdrew from the tournament with a viral illness on Thursday.