While Nadal chases his first US Open crown, Swiss Roger Federer, a finalist at Flushing Meadows the last six years lifting the title five times, is seeded second.
Serb Novak Djokovic is seeded third and Briton Andy Murray, the 2008 US Open runner-up, fourth.
Title holder Juan Martin del Potro of Argentina pulled out of the tournament. He is still recovering from surgery on a right wrist injury that has put him out for almost the whole season.
Andy Roddick is the top American, the 2003 US Open winner seeded ninth.
The USTA will announce the women's seeds on Tuesday due to the Monday finish of the rain-delayed Montreal Cup won by world number two Caroline Wozniacki.
The Dane is expected to be the top women's seed after American world number one Serena Williams was ruled out with an injury.
The US Open starts on August 30.
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