Pro tennis star Serena Williams has decided to end her season.

Williams, who was to play in both the China Open and the WTA Finals, made the announcement on Thursday. 

"It's no secret I've played injured most of the year — whether it was my elbow, my knee, or, in the final moments after a certain match in Flushing, my heart," Williams said in a statement.

Williams hasn't played since losing to Roberta Vinci in the seminfinals of the U.S. Open. She pulled out of next week's China Open in Beijing and the season-ending WTA Flinals in Singapore.