US Open champion Sam Stosur has been critical of her performance against Victoria Azarenka earlier today.
Stosur, 27, rarely threatened her opponent from Belarus, eventually slumping to a 6-2 6-2 defeat in Istanbul.
After the match, Stosur revealed that she was far from satisfied with her display.
"I didn't play aggressive enough. I don't feel like I did anything," she told reporters.
"I just kind of got pushed around the court and, eventually, was made to make an error or she'd hit a winner."
Stosur must now defeat Li Na in her final group match to stand any chance of progressing to the semi-finals.