Roger Federer has withdrawn from the French Open, claiming he would be taking an "unnecessary risk" with his fitness.

Switzerland's Roger Federer reacts as he leaves after losing his semi-final match against Serbia's Novak Djokovic at the Australian Open tennis tournament at Melbourne Park, Australia, January 28, 2016.??[Photo/Agencies]

The 2009 champion at Roland Garros has been struggling for fitness in recent weeks, having withdrawn from the Madrid Open with a back problem before being beaten by Dominic Thiem in the third round of the Internazionali d'Italia.

"I regret to announce that I have made the decision not to play in this year's French Open," he wrote on his official Facebook page.

"I have been making steady progress with my overall fitness, but I am still not 100 per cent and feel I might be taking an unnecessary risk by playing in this event before I am really ready.

"This decision was not easy to make, but I took it to ensure I could play the remainder of the season and help to extend the rest of my career.

"I remain as motivated and excited as ever and my plan is to achieve the highest level of fitness before returning to the ATP World Tour for the upcoming grass court season.

"I am sorry for my fans in Paris but I very much look forward to returning to Roland Garros in 2017."

Federer has been a regular fixture in the latter stages of the French Open since first reaching the last four in 2005, and has only failed to qualify for the quarter-finals on one occasion since - in 2014.

The world number three's withdrawal sees compatriot Stan Wawrinka become third seed at Roland Garros, while nine-time winner Rafael Nadal will avoid a potential quarter-final clash with Novak Djokovic after jumping to fourth.