updated 9:07 p.m. ET Aug. 22, 2008

NEW YORK - Rafael Nadal is faulty at Flushing Meadows, Roger Federer is suddenly shaky. Justine Henin is gone, Maria Sharapova is injured.

Might as well make this the U.S. Wide Open.

The final Grand Slam of the year starts Monday, and this one includes more than its share of wild cards.

“The good thing about tennis this year is that you have many players who are winning some major events,” said No. 3 men’s seed Novak Djokovic. “It’s a bigger competition. It’s more attractive for the fans.”

The first unknown: How will travel trauma affect the stars coming back from Beijing?

Throw in a bad draw for the Williams sisters, a surprising medals sweep by the Russian women at the Olympics, the breakthrough by Ana Ivanovic and a big streak by Juan Martin del Potro, plus James Blake and his rowdy rooters in the J-Block.

Should be plenty to watch over the next two weeks, as matches stretch from before noon to after midnight.

“I know there are some hungry guys ... desperate to make some type of mark,” four-time U.S. Open champion John McEnroe said. “I’d say it’s pretty unpredictable on the women’s side.”

The women’s draw is especially tricky to pick since Henin retired several months after winning her second U.S. Open last year and Sharapova injured her right shoulder. Sharapova doesn’t plan to attend any tennis events, but will be in town for fashion week — maybe that’s where she can bring back her shiny red dress with the 600 crystals.

So start this U.S. Open with Nadal and Federer.

Federer has owned Arthur Ashe Stadium in recent years, winning the last four championships. He often treats the New York crowd to something special, be it a sharp black outfit or a behind-the-back, through-the-legs volley.

But his run toward Pete Sampras’ record of 14 major titles has stalled this season — he’s been shut out, leaving him with 12. Instead, he lost a thrilling, five-set match to Nadal at Wimbledon and fell to his rival at the French Open.

At 27, Federer is no longer unbeatable.

“You don’t ever know when you’re going to see the beginning of the end,” McEnroe said.

“When you lose a little bit of that swagger, guys in any sport pick up on that,” he said. “You work for years to built that invincibility knowing that at some point it’s going to break, the mirror is going to break.”

Fluent in several languages, Federer understands what others are now saying about him.

“I’ve enjoyed it, talking about it, being compared to the greatest,” he said. “It’s a nice challenge ... beating the next generation, trying to play for a long time, trying to stay healthy, trying to beat records.”

“It’s always been difficult to beat all these guys. It’s just not so easy to keep it up all the time. Eventually, sometimes they get you,” he said.

This year, more and more have done it — Andy Roddick, Andy Murray, Djokovic and Blake are among them.

“I think that’s maybe what I feel most this year. You know, just losing too many matches,” Federer said. “I look forward to the U.S. Open. I still have really this and then the Masters Cup in Shanghai to really do well now. Try to save my season.”

While Federer won Olympic gold in doubles, Nadal returns from Beijing with the prize his rival really wanted: the singles titles.

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Ready, Rafa?

Nadal enters the Open at No. 1, having taken over the spot Federer occupied for more than four years. Nadal also is the first top-seeded player at a Grand Slam event other than Federer since January 2004, when Roddick earned that slot at the Australian Open.

Plus, Nadal is 12-6 lifetime against Federer, including victories in all four meetings this season.

“The last years I did very well, too. I was very happy being the No. 2. So finally I’m No. 1,” Nadal said.

“I don’t have time to celebrate. So probably after New York, after Davis Cup, I’m going to have a good time.”

That said, the 22-year-old Spaniard has not done well at the U.S. Open. He’s never advanced past the quarterfinals and lost in the fourth round last year.

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