NEW YORK (AP) -- Past U.S. Open champion Juan Martin del Potro pulled out of the year's last Grand Slam tournament Friday because he's still recovering from wrist surgery.

Del Potro, who beat Roger Federer in the 2009 final at Flushing Meadows, has not played a match on tour since February. His operation was in March.

The 25-year-old Argentine is ranked 11th. The U.S. Tennis Association said his spot in the main draw was taken by 88th-ranked Simone Bolelli of Italy.