Story highlights Federer won the French Open in 2009

Swiss star skipping clay court season to prepare for grass

Won Australian Open in January

(CNN) The speculation is over: Roger Federer will not play in this year's French Open.

The 18-time major champion made the announcement on his website on Monday, a week before the tournament is set to begin.

"I've been working really hard, both on and off the court, during the last month but in order to try and play on the ATP World Tour for many years to come, I feel it's best to skip the clay court season this year and prepare for the grass and hard court seasons," the 35-year-old Federer wrote on the site.

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The ATP is the Association of Tennis Professionals.

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