Venus Williams withdraws from Madrid Open

Former world number one Venus Williams has been forced to withdraw from the Madrid Open due to a back problem, organizers said on Sunday. The 32-year-old

A back injury kept No. 21 Venus off the court, but her sister Serena moved on to the 2nd round in Madrid :: ryan pierse/Getty Images

Former world number one Venus Williams has been forced to withdraw from the Madrid Open due to a back problem, organizers said on Sunday.

The 32-year-old American, now ranked 21, was due to play her first-round match against Spanish wild card Anabel Medina Garrigues on the clay at the premier event on Sunday.

She will be replaced in the draw by 56th-ranked Stefanie Voegele of Switzerland.