(CNN) -- Defending champion Maria Sharapova has been forced to pull out of the Australian Open due to a shoulder injury.
Sharapova has been forced out of the opening grand slam of the season in Australia.
The Russian superstar has been struggling with the injury since the second half of last season and missed both the Beijing Olympics and the U.S. Open.
"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 in a statement.
"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."
It is a shattering blow for the 23-year-old, who dominated last year's opening grand slam of the season.
She did not drop a set on the way to her third career major title, but is frustrated not to be ready for the start of the tournament on January 19.
"The Australian Open is one of my favorite tournaments, they have the best fans in the world and I am going to miss everything about the tournament. I promise I will see everyone next year," she added.
Tournament Director Craig Tiley said he was disappointed for Sharapova because he knows how hard she has been working since the injury which has sidelined her since the Montreal WTA event last August.
"She played some amazing tennis on Rod Laver Arena last year and has a massive legion of fans in Australia. I know she has been working around the clock to try and get back from the shoulder injury. In the end, time beat her this year," he said.
Meanwhile, Serena Williams, the 2007 Australian Open winner, began her build up to the tournament with a hard-fought win at the Sydney International on Sunday.
The former world number one had to stave off four match points in the third set decider before beating Australian Samantha Stosur 6-3 6-7 7-5.