PARIS (Reuters) - Former world number one Kim Clijsters has pulled out of the French Open starting on May 23 because she has not fully recovered from an injury to her left foot, organizers said Friday.

Belgian Clijsters, who returned to competitive tennis in 2009 after a two-year retirement and lies 10th in the WTA rankings, reached the final of the claycourt tournament twice, in 2001 and 2003.

The 26-year-old, who has not entered the French Open since reaching the semi-finals in 2006, will be replaced in the main draw by Canada's Stephanie Dubois.

Russian men's world number six Nikolay Davydenko is struggling with a sore left wrist and has also pulled out, organizers said in a statement.

Davydenko, a semi-finalist in Paris in 2005 and 2007 and a quarter-finalist last year, joins U.S. Open champion Juan Martin del Potro, Tommy Haas, Igor Andreev and James Blake, all also hampered by injuries.

(Writing by Patrick Vignal, editing by Alison Wildey)