Roger Federer and Rafael Nadal could meet in the U. S. Open final in New York for the first time.

Serena and Venus Williams will not be able to reprise their sibling rivalry in the year’s last Grand Slam final.

The No. 1-seeded Federer and No. 3 Nadal were drawn into opposite halves of the field for the U. S. Open, which begins Monday. They have played in seven major finals as Nos. 1-2, including at each of the other three Grand Slam tournaments, with Nadal holding a 5-2 edge.

But because Nadal recently fell to third in the rankings, there was a possibility the two men who have dominated tennis in recent years would wind up on the same side of the bracket in New York.

Instead, 15-time Grand Slam champion Federer has No. 4 Novak Djokovic and No. 5 Andy Roddick in his half. Federer, who is seeking a sixth consecutive U. S. Open championship, edged Roddick, 16-14, in the fifth set of the Wimbledon final in July.

The Williams sisters won’t have a rematch of their Wimbledon final, in which Serena beat Venus for her 11th Grand Slam singles title. That was the sisters’ eighth all-in-the-family final at a major, and Serena leads, 6-2. But at the U. S. Open, the second-seeded Serena and No. 3 Venus were drawn for a possible semifinal.