NEW YORK (AP) - Forgive Roger Federer for having a hard time understanding why there's already been a record 14 players who quit during singles matches through three rounds of this year's U.S. Open.
Federer, after all, never has stopped playing because of injury or illness once a Grand Slam match started.
"For me, it is shocking to see so many retirements," the 16-time major champion said Saturday.
"Look, every player feels different," he added. "It's unfortunate it happens."
Two seeded players, No. 9 Tomas Berdych of the Czech Republic and No. 31 Marcel Granollers of Spain, stopped during their third-round matches Saturday, raising the total retirements in men's and women's singles so far to more than for any entire Grand Slam tournament in the Open era, which began in 1968.
The previous record was the 12 at Wimbledon in 2008, according to the International Tennis Federation. There were 11 retirements in singles at the 2006 French Open and 2003 Australian Open, the ITF said.
Berdych, the runner-up at Wimbledon last year, was trailing 6-4, 5-0 against No. 20 Janko Tipsarevic when he stopped because of an injured right shoulder.
Granollers stopped while behind 6-1, 4-3 against 2003 French Open champion Juan Carlos Ferrero because of an abdominal muscle injury.
There also have been two walkovers at the U.S. Open this year.