By Erik Gudris

(August 15th, 2012) -- Despite the news not coming as a complete surprise, the U.S. Open's announcement that Rafael Nadal had withdrawn from this year's event still sent a wave of disappointment throughout the tennis world.

Patrick McEnroe first broke the news on Twitter this morning that was soon followed by a brief statement from U.S. Open Tournament Director David Brewer that read, "Rafa has informed us that he will not be ready to compete at the U.S. Open this year and has withdrawn from the tournament. We hope to see him back on the court soon and look forward to his return to New York next year.”

Nadal confirmed the news on his own Twitter account by saying, "I am very sad to announce that I am not ready to play the US Open in NY. Thanks to my fans for their support and specially, the new yorkers."

The 2010 U.S. Open champion has been dealing with a severe knee injury since losing in the second round of Wimbledon to Lukas Rosol that forced Nadal out of this month's Olympics where he was a defending gold medalist. Nadal just the other day spoke to Spanish  T.V. channel Laverdad and said that the knee injury is much more severe than previous ones he has had. Toni Nadal was reported to have told a Spanish tennis news site that Nadal wouldn't compete in New York if he was not 100% healthy.

Many players have expressed concern over Nadal's continuing absence from the sport including Roger Federer who during his pre-tournament press conference at the Western and Southern Open said he planned on writing Nadal to check on him after Nadal withdrew from Toronto and then Cincinnati this week.

"I thought for sure we would see him in Toronto, but now he missed Toronto and Cincinnati," Federer said. "It's very surprising, because it was nothing we heard of prior to the injury. He played so well on clay, and then actually seemed fine at Wimbledon. He had more time by losing earlier at Wimbledon. So it came as big surprise now, these two pullouts for me. Even the Olympics, too. So I'm sad for him."

The U.S. Open at Flushing Meadows, New York is scheduled to begin on August 27th.

(Photo Credit: Getty Images)