Friendly rivalry: Federer, Nadal have met in 7 Grand Slam finals, but never at US Open

Roger Federer and Rafael Nadal have played each other 21 times over the years, and all over the world.

Eight matches came at Grand Slam tournaments, and seven of those were in finals: three at Wimbledon, three at the French Open, one at the Australian Open.

The rivals never have faced off at the U.S. Open, though, in any year or in any round. A big reason for that: Nadal has yet to make it past the semifinals in New York. He wants a U.S. Open title, of course. It is, after all, the only Grand Slam trophy he has yet to win.

Still, the No. 1-ranked and No. 1-seeded Nadal insists he is not consumed by thoughts of needing to leave Flushing Meadows with a championship two weeks from now.

"I hope I have another chance to play well here and to have the chance to win — but without obsession, no?" Nadal said. "I am more than happy (with) what I have at home, all the tournaments that I won. More than I dreamt five or six years ago."

Only 24 years old, Nadal already owns eight major titles: five French Opens, two Wimbledons, one Australian Open. But he lost in the semifinals at the U.S. Open each of the past two years and only one other time got as far as the quarterfinals.

"There's not much he's doing wrong," Federer said. "If you can make it to the semis, you can make it to the finals. That's pretty clear."

Federer was one of four past U.S. Open champions scheduled to play in Arthur Ashe Stadium on Monday, along with Andy Roddick, Venus Williams and Kim Clijsters. Another previous winner, Lleyton Hewitt, was slated to be in Louis Armstrong Stadium.

Also in action on Day 1 were Melanie Oudin, the teenager from Marietta, Ga., who made a surprising run to the quarterfinals last year; former No. 1s Dinara Safina and Ana Ivanovic; and this year's French Open finalists, champion Francesca Schiavone and runner-up Sam Stosur.

Nadal was given Monday off, and is expected to be on court Tuesday, facing Teymuraz Gabashvili of Russia in the first round.

"For sure, for me, personal satisfaction is going to be high if any day I have a chance to win here," Nadal said.

First, however, he'll need to reach the final. Federer has participated in every U.S. Open men's championship match since 2004.

"Roger is always there," Nadal noted.

Nadal lost in the second round in 2003 and '04, in the third round in 2005, in the quarterfinals in 2006, and in the fourth round in '07. Then came his semifinal exits against Andy Murray in 2008 and against eventual champion Juan Martin del Potro last year.

In 2008, Nadal says now, he was mentally worn out when he got to the U.S. Open after a busy summer that included winning the gold medal at the Beijing Olympics. Last year, he was physically spent, hampered in particular by an injured abdominal muscle.

There are other explanations cited by Nadal, and others, when discussing why it is that the Spaniard has not joined Federer and the five other men who have completed a career Grand Slam.

The U.S. Open, for one thing, comes toward the end of the season, by which time Nadal's relentless style of play often leaves him relatively beat up. Plus, joints take a particular pounding on the unforgiving hard courts used in Flushing Meadows and at other tournaments on the North American summer circuit.

The tennis balls used at the U.S. Open, Nadal explained, are different from those at the French Open, for example, and don't allow him to slather shots with as much topspin as he likes to use. And 23,771-seat Arthur Ashe Stadium, the largest arena in Grand Slam tennis, always seems to be quite windy, which Nadal said he finds troublesome.

All of that said, Nadal's contemporaries would not be surprised to see his name etched on the silver U.S. Open trophy one day.

"I'm not going to sit here and say he can't win it. Of course he can win it," said Roddick, the 2003 champion seeded ninth this year. "What's the prevailing thought, except that he hasn't done it yet? He's done everything else. He's won on hard courts. He's won on slow hard courts. He's won on fast courts. He can handle the pressure. Will he? I don't know. But can he? Sure."