NEW YORK — Ten top topics at the U.S. Open, 2013's last Grand Slam, which begins Monday:
MURRAY'S DEFENSE: For the first time, Andy Murray is the defending champion at a Grand Slam, and he suspects he'll be more nervous than usual early.
RAFA RETURNS: Rafael Nadal has had many ups and downs the past two seasons, including a seven-month absence because of knee trouble — he missed two Grand Slams, including last year's U.S. Open — plus two more French Open titles and two quick Wimbledon exits. He improved to 15-0 on hardcourts in 2013 by winning at Montreal and Cincinnati this month.
FEDERER AT NO. 7: Roger Federer turned 32 this month, has fiddled around with a bigger racket, is coming off his earliest loss at a Grand Slam in a decade and is seeded No. 7.
ANYONE OUTSIDE THE 'BIG 4'? Federer, Nadal, Murray and Novak Djokovic have won 33 of the past 34 Grand Slam titles, a stretch that began in 2005. A discussion of other contenders must begin with the guy who kept it from being 34-of-34, Juan Martin del Potro, who beat Federer in five sets in the 2009 U.S. Open final. Another big hitter to keep an eye on is Tomas Berdych.
THE AMERICAN MEN: This U.S. Open is the 40th Grand Slam since an American man won a major title, Andy Roddick at the U.S. Open in 2003. Tampa resident John Isner, who can serve as well as anyone, is seeded 13th.
WILLIAMS' repeat trouble: One thing missing from Serena Williams' resume is a successful U.S. Open title defense. She won her fourth Open trophy last year. Williams is seeded No. 1. The last time that happened in this tournament was 2002, and she won.
notable absence: Maria Sharapova withdrew last week, citing shoulder trouble, leaving the field without one of the sport's top stars.
YOUNG u.s. WOMEN: Sloane Stephens, 20, is seeded 15th. She upset Williams en route to the Australian Open semifinals this year, made it to the Wimbledon quarterfinals before losing to eventual champion Marion Bartoli and got to the second week at the French Open. Jamie Hampton, 23 and seeded 23rd, made the French Open's second week. Madison Keys, 18, is worth watching, too.
MONDAY, MONDAY: For the first time in the Open era, which began in 1968, the U.S. Open is scheduled to end on Monday, a result of a push by top players for a day of rest between the men's semis and final instead of the Open's long-standing Saturday-Sunday finish. Each of the past five Opens wrapped up on Monday but because of rain delays.
MONEY, MONEY: Another result of lobbying by top players, the Open is raising its total payout about 35 percent from last year, to more than $34 million.