U.S. Open warm-up tournaments in New Haven and Winston-Salem have been hit with a rash of withdrawals and retirements.

On Monday, Winston-Salem lost its only two Top 20 players in Tomas Berdych (shoulder) and John Isner (hip) to injuries sustained in Cincinnati. Young American Jack Sock was also a casualty, retiring with a right leg injury in the third set of his first-round match against David Goffin.

Isner grew up in nearby in Greensboro, North Carolina. He defeated Berdych, 3-6, 6-4, 7-6 (9), in the 2012 Winston-Salem final.

“I don’t foresee an instance where I don’t plan on playing this tournament,” he told reporters. “Two years ago coming into this tournament, I wasn’t playing as well, and I won the tournament and made the quarterfinals of the U.S. Open. There are pros and cons of playing the week before, but I have always been a guy, I play the week before a Grand Slam. This year is a little different because I think I would put myself at further risk.”

On Monday in New Haven, Magdalena Rybarikova and Urszula Radwanska pulled out prior to their matches, while Peng Shuai, Sorana Cirstea, and Ayumi Morita retired with injuries.