Russia's Maria Sharapova has pulled out of the Rome Open, citing "physical problems", the WTA said on Friday.
The two-time winner of the tournament and world number two had been due to play Italy's Sara Errani in the quarter-finals.
Errani, the world number six, will now go through to the semi-finals to meet the winner of the match between Australia's Samantha Stosur and Viktoria Azarenka of Belarus.