NEW YORK — Mardy Fish, the 23rd-seeded American who withdrew from his scheduled fourth-round match against top-seeded Roger Federer earlier Monday, issued a statement that didn't clarify the exact reason for his withdrawal.
"I regret that I have to withdraw from the U.S. Open for precautionary measures," the statement said. "I was reluctant to do so but am following medical advisement. I had a good summer and look forward to resuming my tournament schedule in the fall."
Fish, a 30-year-old who missed part of this season after having treatment for an irregular heartbeat, has a 1-8 career record against the 31-year-old Federer.
Fish had played listless, error-filled tennis in his third-round match, a 6-1, 5-7, 7-6 (5), 6-3 win over 16th-seeded Gilles Simon, who had been hampered by a shoulder injury that kept many of his first serves less than 100 mph.