Serena Williams is unlikely to play again this year after

failing to shake off a foot injury.

The American has not played since winning

Wimbledon in July after cutting her

foot in a restaurant but has trained in recent weeks with a view to

playing in the Generali Ladies Linz event in Austria this week.

But she has had to delay her comeback, revealing she has

re-strained her foot by over-training.

In a posting on her official website on Sunday, Williams said:

”I have been training for many weeks to get back to playing tennis

as quickly possible since my foot surgery in mid-July.

”Yesterday I learned that I had tried too hard, and did too

much too soon. After practising yesterday morning I felt discomfort

in my foot and tests by my doctor revealed that I had unfortunately

re-strained it, as a result of over training.

”I am likely out for the year now. I was really looking forward

to beginning my comeback in Linz, followed by the year-end

championships in Doha. I feel completely heartbroken, and

devastated, but I plan on coming back stronger and better.”

Tournament organisers confirmed Williams’ withdrawal from the

tournament in Linz yesterday.

Williams will lose her world number one spot when the latest WTA

rankings are published today, after 20-year-old Dane Caroline

Wozniacki secured top spot by reaching the quarter-finals at the

Beijing tournament.