Top-ranked Novak Djokovic and No. 4 Victoria Azarenka both say they have recovered from injuries. Djokovic pulled out of the Cincinnati final with a shoulder injury, while Azarenka did not play Cincy due to a wrist injury.

"The shoulder in Cincinnati didn't feel good obviously, and throughout the whole week I was carrying the kind of pain and discomfort," Djokovic said after he advanced to the second round of the U.S. Open when his foe, Connor Niland, retired due to food poisoning "But after Cincinnati I took some time off, and I did everything in order to recover the shoulder. Today I didn't feel any pain. I served well and I played well, so I have no concern."

Azarenka, who also won her first-round match, added: "I prepared really well. I'm not feeling my hand so I'm ready to go."