After numerous withdrawals of big name players already, including Maria Sharapova and Ana Ivanovic, the Fed Cup has suffered another blow with Serena Williams announcing she will also be unavailable.

On Tuesday, Serena confirmed she will not play in next week's Cincinatti event, but did not make it clear if would play in this weekend's Fed Cup semi final against Russia in Vermont. Williams said she is still recovering from a hand injury she sustained at Wimbledon as well as the calf injury which forced her to fall to the ground in pain in her fourth round clash with Daniela Hantuchova.

World number 41 Meilen Tu will be Williams' replacement.