NEW YORK (AP) Roger Federer says ``it's been hard to watch'' his pal Tiger Woods struggle lately.

``It's hard to follow, because you know what an athlete wants to do. He wants to be out there and compete and that's what he's not able to do with his injuries right now,'' Federer said Saturday after a third-round win at the U.S. Open.

Federer and Woods used to take part in a friendly competition over who would reach the Grand Slam record in their sport first. Federer tied Pete Sampras' mark of 14 at the French Open in 2009 and broke it two months later at Wimbledon. He's now at 16.

Woods, meanwhile, remains stuck on 14 - four short of Jack Nicklaus - without a major victory since the 2008 U.S. Open at Torrey Pines.