The five biggest questions from the first week of the U.S. Open

Patrick Mouratoglou is a world-renowned tennis coach who has worked with Marcos Baghdatis and Aravane Rezai. His French tennis academy is considered one of the best in the world. He'll provide commentary for Busted Racquet during the 2010 U.S. Open.

Now that we're in the second week of the U.S. Open, it's time to look at a few of the biggest questions that have emerged so far:

Where does Andy Murray go from here?

The world No. 4 needs to start thinking about getting a coach. He's showing way more perseverance than others without coaches, but he really needs to find someone to guide him now. This loss against Stanislas Wawrinka is a huge disappointment. His body let him down. The Scotsman has seen his whole game style implode from Toronto to New York. There was too much defensive play, no inspiration and a lot of searching for easy answers instead of setting up a real game plan. Murray showed all his limits. He's a great player but lacks the refinement right now to get a first Grand Slam win.

Is Federer's back giving him trouble again?

Roger Federer and Rafael Nadal are on a crash-course for the final. They're playing convincing tennis at the moment, as none of them has dropped a single set until now. The Spaniard is playing really aggressive tennis. He's searching for flat shots, which has helped so far but could be a liability against effective counter-punches. Concerning Federer, you have to say that I'm worried lately. His wins over Mathieu and Jurgen Melzer left me with a bitter taste. I thought I've noticed some signs of pain in his back. He seems to be lacking some initiative and has been very static in his footwork, not getting down enough on his legs. It looks a lot different than his style in Toronto and Cincinnati.

What happens to Marcos Baghdatis and David Nalbandian?

Both players came back from injuries this summer with gusto, but how long can they keep it up? You can't get back to a Grand Slam final just because you've found motivation for three months. Getting into the last four of such an event requires a real project, a long-term involvement in training and focus. It's a long building process and that's why those tournaments are different: You can't just arrive and get it in a snap. Winning at a Slam is a totally different thing to achieve and these two aren't at that level at the moment.

Who wins on the men's side?

When you give a look to the top of the draw it's hard to see Nadal being challenged. He has Feliciano Lopez on Tuesday night and then David Ferrer or Fernando Verdasco. Wawrinka or Querrey likely follows that. Unless there's a huge surprise, he'll be a finalist this year and, in my opinion, he'll also be the favorite to win it. Federer is facing a much tougher draw. He'll have first to get rid of Robin Söderling, which he should be able to do, but then he could face Novak Djokovic. That would be a really difficult task. Physical conditioning is going to be the key because trying to overcome Djokovic and Nadal back-to-back requires Fed to be in the best of shape. We'll know more about this after his match against Söderling.

Is Wozniacki the favorite?

There haven't been many surprises in the womens' draw either. Caroline Wozniacki and Kim Clijsters confirm how strong they are this year. Much like the men's top two seeds, they've not dropped a single set. We could get a rematch of last year's final. The Dane played flawlessly in her match against Maria Sharapova, committing very few unforced errors, reading the Russian's game easily and confirming once again how much she has improved her serve. Compared to last year, she now knows how to take advantage of each short ball and she uses her serve much more effectively. She should get over Dominika Cibulkova and Vera Zvonareva to climb to the final. Clijsters has a more difficult task. She'll have to battle against Sam Stosur, who won that epic fight against Elena Dementieva. But the Australian may arrive very tired after such a thriller. If she wins that one, the Belgian would likely face Venus Williams. But the American hasn't been fully convincing in the first week. She has been struggling with ups and downs in all her matches, so she'll be the clear underdog against Kim. As a result, I'll be very surprised if this year we don't see a replay of the 2009 final.