Paris - Sweden's former world No 4 Robin Soderling on Thursday ruled himself out of the Australian Open, the first Grand Slam event of 2012, as he struggles to conquer mononucleosis.
The 27-year-old has not played since mid-July when he captured the Bastad title, his fourth trophy of the season.
"My recovery has been longer than expected," he wrote on his Twitter account.
"I am feeling better with each day but it will still take some time before I can start practicing in full speed. My goal is to start with practice in January and I hope for a tournament comeback in February but at this stage it is hard to know when and where. I hope my body will allow me to do that."
Soderling, twice a French Open runner-up, is currently ranked No 13 in the world.
The Australian Open gets underway in Melbourne on January 16.