Silly as it sounds nowadays, there was a time when some in the tennis world wondered whether Roger Federer was equipped to handle the US Open.
Even Federer himself harbored doubts. It took him longer, after all, to get past the fourth round at this Grand Slam tournament than any other.
"Hey, New York is a crazy place," he said in a recent interview. "There's the night. There's the humidity. There's the heat. There's the city. There's the wind. ... If you can win the US Open, you can win anything."
Federer, of course, overcame all of those factors to take the past three championships at Flushing Meadows, part of his haul of 11 Grand Slam titles -- three shy of Pete Sampras' record. When play begins on Monday at the year's last major, Federer will be trying to become the first man since Bill Tilden in the 1920s to win the American Slam four times in a row.
Now it's another top player's turn to prove he can deal with all of the challenges the US Open presents: Rafael Nadal. His career record of 8-4 in New York is his worst at any major.
Last year, the Spaniard reached the Open's quarter-finals for the first time, yet here was his assessment then: "I cannot say I am very happy with my tournament. I want to play the final in every tournament. I know that's impossible, but I'm going to try, no?"
After No. 1 vs. No. 2 showdowns at the French Open and Wimbledon, Federer and Nadal can become the first pair of men to contest three consecutive Grand Slam finals since Ken Rosewall and Fred Stolle in 1964-1965.
Nadal beat Federer twice for the title on clay at Roland Garros. Federer beat Nadal twice for the title on grass at the All England Club. So the hard courts of the Billie Jean King National Tennis Center could provide a tiebreaker of sorts in what's become a riveting rivalry.
There is a lot more parity in the women's game, with five players splitting up the past five majors. Four -- No. 1 Justine Henin, No. 2 Maria Sharapova, Serena Williams and Venus Williams -- have already won the US Open at least once and are the top contenders this year, although each has had recent injuries. The fifth, Amelie Mauresmo, withdrew because of health concerns.
Two other players, both from Serbia, appear on the verge of a first major title: Jelena Jankovic and Ana Ivanovic.
As is often the case, the true wild cards are the Williams sisters. Serena Williams, whose eighth major title came at January's Australian Open, hasn't played in a month and a half because of a thumb injury. Venus Williams won Grand Slam No. 6 at Wimbledon, then entered only one tournament since and lost in the quarter-finals.
Still, other players know they have to watch out for the Williams family.
Here's what defending US Open champion Sharapova said about Venus: "I know what she's capable of. I know she can produce great tennis. That's what has won her so many Grand Slams, kept her at the top."
Mainly because of a lack of activity, the sisters have seen their rankings fall from those heady times when they were meeting in Grand Slam final after Grand Slam final -- the way a couple of guys have been doing lately.