Maria Sharapova has been forced to withdraw from next week's Australian Open due to injury. The reigning champion has not played since August because of a nagging shoulder complaint, but she had hoped to be ready for the first grand slam of the year.

"I am very sorry to announce that I am not going to be able to defend my title at this year's Australian Open," Sharapova said. "My shoulder is doing great, but I just started training a few weeks ago and I am just not near the level I need to be to compete at the highest levels."

The 23-year-old Russian dominated the tournament last year, not dropping a set on her way to her third major success. "The Australian Open is one of my favourite tournaments, they have the best fans in the world and I am going to miss everything about the tournament," she said. "I promise I will see everyone next year."

Craig Tiley, the tournament director, was disappointed for Sharapova because he knows how hard she has been working since the injury and how much she wanted to defend her crown. "She played some amazing tennis on Rod Laver Arena last year and has a massive legion of fans in Australia," he said. "I know she has been working around the clock to try and get back from the shoulder injury. In the end, time beat her.

"We wish her well with her return to tennis and look forward to seeing her back in Melbourne next year, Maria is always welcome here."

Prize money for the Australian Open has increased this year, with the singles winner each receiving £927,000 and the runners-up £464,000. Tennis Australia has increased the overall prize pool for Australian Open 2009 by 12.3 per cent to a total figure of £10.7 million with all of the increase going to the singles finalists.

"As the President of the Player Council and on behalf of all the ATP players, I want to thank Tennis Australia for acknowledging the players' role in helping to make the Australian Open one of the greatest tennis tournaments in the world," Roger Federer, the world No 2, said. "The increase in prize money, even in these tough economic times, is a positive symbol of Tennis Australia's commitment to rewarding the players for their role as a partner in the Australian Open."