American Mardy Fish withdrew from the U.S. Open on Sunday due to a rib injury he has sustained. The 25th seeded Fish was to face Daniel Koellerer of Austria in his opening match. Koellerer will instead face Rui Machado of Portugal.

Fish who made the quarterfinals at the Open last year, would have been hard pressed to repeat that performance this year. He was set to meet up with 6th seeded Juan Martin Del Potro in the third round.