Top-ranked Rafael Nadal's path to his first U.S. Open title could be blocked by a potential semifinal match against Britain's No. 4 Andy Murray, set up when Murray landed in Nadal's half of the 128-man field at the tournament's draw ceremony Thursday.
In the opposite half, No. 2 seed Roger Federer, five times the Open champion, theoretically should have no trouble until a possible quarterfinal against Sweden's Robin Soderling, who upset Federer in this year's French Open quarters.
With the women's No. 1 player, Serena Williams, sidelined by a foot injury, 20-year-old Dane Caroline Wozniacki, last year's Open runner-up, moved into the top seed position, but drew two former Open champions into her quarter-No. 14 Maria Sharapova and No. 11 Svetlana Kuznetsova. All three have played well on the summer hardcourt circuit.
The most well-stocked quarter of the women's draw, at least in terms of familiar names, was the one including defending champion Kim Clijsters, seeded second. Along with Clijsters, who said she is healthy after a recent hip problem, are two other former No. 1 players, Russia's Dinara Safina and Serbia's Ana Ivanovic -- both struggling lately -- as well as No. 5 Samantha Stosur of Australia, this year's French Open runner-up, and unpredictable but occasionally dangerous No. 12 Elena Dementieva of Russia.
Whoever survives that quarter likely would face No. 3 Venus Williams, who could meet Italy's Francesca Schiavone, the reigning French champion, in the opposite quarterfinal, though Schiavone might not get past a potential fourth-round challenge from Victoria Azarenka of Belarus. Melanie Oudin, the 18-year-old Georgian who was a surprise quarterfinalist last year, also is in Schiavone's section, scheduled to begin play against a yet-to-be-named qualifier.
Another former No. 1, Jelena Jankovic of Serbia, does not appear to be in any early danger until the quarterfinals; if form follows, she would then play either No. 7 Vera Zvonereva of Russia or No. 9 Agnieszka Radwanska of Poland.
Among the men, tennis experts see No. 9 Andy Roddick and No. 19 Mardy Fish as the most likely Americans to move deep into the tournament, but they would have to play each other -- if they make it that far -- in the quarterfinals.
First, Fish probably would face another of the summer's hot players, No. 16 Marcos Baghdatis of Cyprus, in the third round and most likely No. 3 Novak Djokovic in the fourth. If seeding form holds, Roddick would meet No. 6 Nikolay Davydenko of Russia in the fourth round.
The other two Americans of note this year, No. 18 John Isner and No. 20 Sam Querrey, are in the same quarter with two men who already have been to Grand Slam finals, Murray and the Czech Republic's Tomas Berdych.