Serena Williams 'injures foot again'

Serena Williams has revealed that she recently injured her foot and will be unable to play tennis during the upcoming season.

The athlete previously underwent surgery after stepping on glass at a German club last summer but recently began training again for an upcoming tournament, during which she hurt herself further.

"Yesterday I learned that I had tried too hard, and did too much too soon," she wrote on her official blog.

"After practising yesterday morning I felt discomfort in my foot and tests by my doctor revealed that I had unfortunately restrained it, as a result of over training."

Williams continued: "I am likely out for the year now... I feel completely heartbroken, and devastated, but knowing I will never be given more than I can handle I plan on coming back stronger and better."