Serena Williams says she has re-torn the tendon in her right foot and will not play the WTA year-end championships in Doha or the Fed Cup final against Italy.
After cutting her feet and undergoing surgery in July, Williams said she had another procedure on the foot on Monday.
"It is with deep frustration that I am withdrawing from the WTA Championships at Doha and the Fed Cup final. Pushed by my desire to return to competition, I trained too hard too soon and re-tore the tendon in my foot," she said in a statement. "As a result, yesterday morning I had to have another procedure to repair it.
"I thank everyone for their continued support during this difficult time and look forward with strength and determination to getting back on the court."