Winston Salem - Two-time defending champion John Isner and top-seeded Czech Tomas Berdych on Monday withdrew from the ATP Winston Salem Open, both citing injury.
The event is now left with Italian Andreas Seppi as the top-ranked player in the last tournament prior to the start of the US Open in a week.
"I've had so much success playing in front of great crowds as well as my friends and family," said Cincinnati finalist Isner 24 hours after losing to Rafael Nadal in Ohio.
"This was a really tough decision but with injuries (knee) taking me out of the Australian Open and Wimbledon, I need to fully heal prior to the US Open."
Isner has won the only two editions ever played in Winston Salem, an event which was moved to the southern city in 2011.
He beat Berdych for the 2012 title.
The American pulled out after speaking to doctors about his condition.
He had already begun hedging his bets in Cincinnati, saying he would head to the next tournament and see how he felt on the day.
Berdych claimed a shoulder problem while Isner, called it off due to a hip injury.
Lucky losers in the qualifying round will replace the seeded pair in the tournament draw.