By Lauren Lynch                 Photo Credit: Natasha Peterson/ Corleve

(September 30, 2011) Maria Sharapova was forced to pull out of the China Open due to injury and Serena Williams is out because of a mysterious draw.

US Open finalist Williams will not be at the China Open for the second time in a row. She was not included in Friday’s draw for an unexplained reason.

The American won the Beijing women’s singles title in 2004. Last year she had to drop out due to her foot injury but it is unclear so far.

Current World No. 2 Sharapova twisted her left ankle in the Toray Pan Pacific quarterfinals that put her out of commission. Sharapova is trying to make the WTA Championships beginning October 25 in Istanbul.

On her website, she reported, "good news is that the MRI showed no big damage in the ankle."

The China Open begins Saturday in Beijing.