Venus Williams pulls out of Madrid Open

Associated Press, Madrid,Spain | Sports | Sun, May 05 2013, 5:25 PM

Venus Williams has withdrawn from the Madrid Open due to back problems.

The American player was set to open the tournament on Sunday.

Her sister, top-ranked Serena Williams, will begin her tournament against Yulia Putintseva of Kazakhstan later.

Switzerland's Stefanie Voegele will take Venus' place in the first round against Anabel Medina of Spain.