IMAGE: Serena Williams reacts. Photograph: Geoff Burke-USA TODAY Sports/Reuters
Women's World No 1 Serena Williams has withdrawn from the Madrid Open because of flu, the organisers said on Friday.
'Don't be surprised if Serena is no longer No 1 by end of the year'
"Unfortunately, I have to withdraw from Madrid because I've been battling the flu and I'm not at 100 per cent. I look forward to returning soon," Williams said.
Agnieszka Radwanska is now the top seed at the tournament staring on Saturday.
