Djokovic, after all, is seeded No. 1, and Nadal is No. 2. Djokovic owns six Grand Slam titles, Nadal 12.
Each already won the U.S. Open once, with Nadal beating Djokovic in the 2010 final, and Djokovic beating Nadal a year later. They've met in five major finals in all.
And their semifinal opponents Saturday? Well, Djokovic's 14th consecutive Grand Slam semifinal — a streak that ranks second in men's tennis history to Roger Federer's 23 in a row — comes against No. 9 Stanlisas Wawrinka, who will be making his debut at this stage of a major tournament. And Nadal plays No. 8 Richard Gasquet, who was 1-15 in fourth-round Grand Slam matches until this tournament and will be appearing in only his second major semifinal.
Even before Wawrinka had upset defending champion Andy Murray in the quarterfinals, and before Djokovic got past 21st-seeded Mikhail Youzhny, Nadal was asked whether he's ready to beat Djokovic in the final.
"Do you think Djokovic will be in the final? I don't know if I will be, so I hope to be ready to play a good match against Richard," Nadal said, laughing. "If I don't play (a) great match against Richard, I will see the final on TV."
All four men have been saying the right things: Djokovic and Nadal talk about how great their upcoming foes are, and how difficult the task at hand will be; Wawrinka and Gasquet talk about believing in their chances.
Listen to Djokovic describe Wawrinka: "He's a very complete player. He can play equally well on any surface."
Nadal on facing Gasquet: "I hope to have my chances."
Djokovic also talked up Gasquet: "Richard was always one of the most talented players that played the game and one of the most beautiful and also most efficient backhands that we have seen."
Then, of course, there are the head-to-head records to take into account.
Gasquet has lost all 10 tour matches he has played against Nadal, prompting jokes about how the Frenchman did actually win once when they were 13 years old. Wawrinka hasn't fared too much better against Djokovic, going 2-12, with 11 losses in a row. On the other hand, the last time they played — in the fourth round of the Australian Open in January, on a hard court — Djokovic barely emerged as the winner, 12-10 in the fifth set.
Wawrinka points to that match as the catalyst for his career-best season, which reached its zenith so far with his 6-4, 6-3, 6-2 victory over Murray. That result Thursday, surprising in large part for its swiftness, also should give hope to Wawrinka (and maybe even Gasquet) for the semifinals.
Murray played poorly, certainly, but Wawrinka truly seized the moment, playing an attacking brand of tennis that could provide an intriguing contrast to — and challenge for — Djokovic's terrific, chase-every-ball-down defence.
"He hit a lot of lines, was going for big shots, and he played too well," was Murray's summation of Wawrinka's performance.
For the better part of a decade, dating to the 2005 French Open, Nadal, Djokovic, Federer and Murray have combined to win 33 of the past 34 Grand Slam titles (the exception was Juan Martin del Potro's 2009 U.S. Open championship).
"In tennis, as you know, if (you) are not Roger or Rafa and Djokovic or Andy now, you don't win so many tournaments," Wawrinka said, "and you always lose."
Well, if Wawrinka can beat Murray, if Robredo can beat Federer, if Gasquet can finally win another Grand Slam fourth-round match, then who knows what can happen?
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