Novak Djokovic exposed a chink in his otherwise impenetrable suit of armor when he retired in the Cincinnati final, effectively handing the title to Andy Murray. Then again, he had just come off a Masters win in Montreal to make a run through the Cincy draw. That's a lot of matches. If he's well-rested and allows his shoulder some recovery time, look for top-seeded Djokovic to stay true to form and cruise through the draw to contend for his first US Open title and third major of the year.

See the women to watch

Rafael Nadal's confidence has surely been shaken this summer after the World No. 2 and defending US Open champion suffered an stunning second-round loss in Montreal to Ivan Dodig and a quarterfinal loss to Mardy Fish in Cincinnati. But, he is Nadal. He's won in New York before. He's won the French Open this year. A repeat title is possible.

Roger Federer and the US Open go together like Rafael Nadal and Roland Garros or Roger Federer and Wimbledon. Though No. 3 in the world, Federer knows how to win in New York, holding the title for five straight years (2004-2008). He reached the final in 2009 and the semis in 2010 and the 29-year-old is the only player to have legitimately beaten No. 1 Novak Djokovic this year. As they say, it ain't over 'til it's over and Federer is nowhere close to finished.

Mardy Fish eclipsed Andy Roddick as the top-ranked American and has held his ground this summer winning the title in Atlanta and reaching the finals in Los Angeles and Montreal. Fish also reached the semis in Cincinnati last week. If Fish continues to play at a high level, look for him to go deep into Week 2.

Andy Murray remains the only one of the top four without a Slam to his name, but this year he's come very close reaching the Australian Open final and the French Open and Wimbledon semis before losing to Novak Djokovic (Australian Open) and Rafael Nadal (French and Wimbledon). Even though Djokovic retired in the final, Murray heads to New York after claiming the title in Cincinnati and if the rest of the year is any indication, he should wind up in the at least the semifinals.

American veteran Andy Roddick enters the 2011 US Open with the 21 seed. At 28, the 2003 winner seems to be fading into the sunset a bit, but in New York, anything can happen. Roddick certainly isn't a serious contender this year, but his serve should never be taken lightly.
 

The 2009 US Open champion is out to prove he's not a one-hit wonder. After sitting 2010 out following shoulder surgery, del Potro has faced a long road back, but has slowly rejoined the top 20 once again. Look for the No. 18 seed to make some noise at least through week one.

Does Ryan Harrison have a shot at winning the 2011 US Open? No. Will he see the second week in New York? Perhaps, but we're not counting on it. So why should we care? This summer Harrison has shown he's got the meddle to stand up and take the reins and lead the next generation of US players. The 19-year-old began the summer ranked No. 120 in the world and enters the US Open at No. 67 after reaching the final in Atlanta and semifinals in Los Angeles, losing to Mardy Fish both times.
 

France's Jo-Wilfried Tsonga didn't play last year's US Open, but after reaching the Wimbledon semis in June he now knows how to advance through a draw when it counts. The No. 11 seed is somewhat erratic. He can be dazzling one minute and downright dismal the next, but as we saw in his huge Wimbledon quarterfinal upset over Roger Federer, when he's on, he's on.

While John Isner, Gael Monfils and Robin Soderling shouldn't pose a huge threat to the top four, they can surely pose a threat to the rest of the draw. Isner's serve, Monfils' tenacity and Soderling's experience are enough to make any opponent step up his game.