Washington - Defending champion Svetlana Kuznetsova has pulled out of the Citi Open, citing an injury to her lower left leg.
The tournament announced her withdrawal on Wednesday night.
"I am so sorry to have to do this, but my body doesn't feel up to it," Kuznetsova said.
The fourth-seeded Kuznetsova, who owns two Grand Slam singles titles, won her first-round match easily on Tuesday, beating qualifier Sanaz Marand in straight sets.
Kuznetsova's departure means that the woman she was supposed to play next, Sloane Stephens, moves into the quarter-finals.