Serena Williams undergoes toe surgery

World number three Serena Williams has withdrawn from her scheduled exhibition match against Victoria Azarenka after undergoing toe surgery.

Williams was due to meet the world number one in Thailand later this month, but surgery on her big toes has seen her pull out of the clash.

She told reporters: "I am being advised by my doctors to take more time to heal following a minor procedure I needed to address my ongoing foot issues."

It is understood that Li Na has replaced Williams for the clash at the end of December.