2012 U.S. Open preview

What: Fourth and final Grand Slam tennis tournament of the year.

When, where: Monday through Sept. 9; USTA Billie Jean King National Tennis Center.

TV, online: CBS, CBS Sports Network, ESPN2, Tennis Channel; www.usopen.org

Last year: Novak Djokovic won his first U.S. Open title, coming back to erase match points and beat Roger Federer in the semifinals, before beating defending champion Rafael Nadal 6-2, 6-4, 6-7 (3), 6-1 in the final. Sam Stosur of Australia dominated Serena Williams 6-2, 6-3 in the women's final to earn her first Grand Slam trophy.

1. Roger Federer, Switzerland

2. Novak Djokovic, Serbia

3. Andy Murray, Great Britain

5. Jo-Wilfred Tsonga, France

6. Tomas Berdych, Czech Republic

7. Juan Martin del Potro, Argentina

8. Janko Tipsarevic, Serbia

1. Victoria Azarenka, Belarus

3. Maria Sharapova, Russia

4. Serena Williams, United States

5. Petra Kvitova, Czech Republic

6. Angelique Kerber, Germany

7. Sam Stosur, Australia

Resurgent summer: Roger Federer, back atop the world rankings, is pursuing a sixth U.S. Open championship at age 31.

No Nadal: Rafael Nadal, the 2010 U.S. Open champion and runner-up a year ago, pulled out of the tournament because of bad knees.

Red, white and blue: No American man has won the U.S. Open since Andy Roddick in 2003. The highest-seeded American man is No. 9 John Isner.

Coming off gold: Serena Williams will attempt to win her 15th major trophy -- and stay out of trouble with on-court officials.

Farewell, Kim: Three-time U.S. Open champion Kim Clijsters, 29, says this year's tournament will be the last event of her career. She has a 21-match winning streak at the Open.