NEW YORK -- Mardy Fish of the United States withdrew from the U.S. Open on Sunday because of a rib injury.
The 25th-seeded Fish, of Tampa, Fla., was a quarter-finalist at Flushing Meadows last year.
He had been drawn to face Daniel Koellerer of Austria in the first round. Instead, Koellerer will play Rui Machado of Portugal.
Fish lost in the second round of last week's hard-court tuneup in New Haven, Conn.