Andy Murray and Serena Williams lined up at this year's US Open

Ahead of the start of the final major tournament of the year, the US Open, which begins on Monday, here is a look at some of the major talking points at Flushing Meadows. Murray's first defence For the first time, Andy Murray will be the defending champion at a grand slam tournament – and he suspects he will be more nervous than usual in the early rounds. It will be intriguing to see if that is true. His championship at the 2012 US Open made him the first man from Britain to win a major title since Fred Perry in 1936. And last month, Murray ended Britain's 77-year wait for a male champion at Wimbledon. Nadal returns Rafael Nadal has gone through all manner of ups and downs over the past two seasons, including a seven-month absence because of knee trouble – he missed two grand slam tournaments, including last year's US Open – plus two more French Open wins and two quick exits at Wimbledon. He has looked terrific lately, improving to 15-0 on hard courts in 2013 by winning the Montreal and Cincinnati tournaments this month. He is back to No 2 in the rankings, behind only Novak Djokovic, who has reached at least the semi-finals in each of his past six visits to Flushing Meadows. Federer is No 7 Roger Federer 's 17 grand slam titles include five at the US Open. He was ranked No 1 for more weeks than any man in history. He was seeded No 1 at 18 consecutive major tournaments from 2004-08. And now? Well, he turned 32 this month, has fiddled around with a bigger racket, is coming off his earliest loss at a grand slam tournament in a decade, and is seeded No 7 at the US Open. If he makes it to the quarter-finals, he would face his nemesis, Nadal. Outside the big four The so-called big four of Novak Djokovic , Nadal, Federer and Murray have combined to win 33 of the past 34 majors, a run that began in 2005. Is there any chance anyone else breaks through at this tournament? Any discussion of other contenders must begin with the guy who kept it from being 34 of 34 – Juan Martin del Potro, the Argentine with the booming forehand who surprised Federer in five sets in the 2009 US Open final. Another big hitter to keep an eye on is No 5 Tomas Berdych, the 2010 Wimbledon runner-up, although consistency is not his strong suit. American men Andy Roddick's name might very well be mentioned as much over the coming weeks as Perry's has been uttered at Wimbledon. This US Open is the 40th grand slam tournament since an American man won a major title, dating to Roddick's victory at Flushing Meadows in 2003. Earlier this month, for the only time in the 40-year history of the ATP computer rankings, no US male appeared in the top 20. The big-serving John Isner has subsequently moved back in; he is seeded 13th and could play Nadal in the fourth round. Williams aims for two For all Serena Williams has accomplished, one tiny thing missing from her resume is a successful title defence at the US Open, the site of a couple of her infamous meltdowns. She won her fourth trophy at Flushing Meadows last year, edging No 2 Victoria Azarenka in a three-set final. Williams is seeded No 1 in New York – the last time that happened was 2002, and she won the tournament. Absentees Maria Sharapova withdrew the day before the draw due to injury, weakening the women's draw. Wimbledon champion Marion Bartoli is not in New York, either, because she suddenly announced her retirement this month at age 28. Also absent is Mardy Fish, who used to be ranked in the top 10 and was a quarter-finalist in New York two years ago, but has not played in a grand slam tournament in 2013 as he tries to come back from a heart issue. Young American women Sloane Stephens is seeded 15th, and the sport's biggest stages bring out her best tennis: She upset Williams en route to the Australian Open semi-finals, made it to the Wimbledon quarter-finals before losing to eventual champion Bartoli, and got to the second week at the French Open, too. Stephens, 20, is not the only up-and-coming American who could draw attention. Jamie Hampton, who is seeded 23rd, also made the second week at Roland Garros. Madison Keys is worth watching, too. In all, there are 10 US women in the WTA's top 100. Monday finish For the first time in the Open era, which began in 1968, the year's last grand slam tournament is scheduled to end on a Monday – a result of the push by top players to provide a day of rest between the men's semi-finals and final, instead of the US Open's long-standing Saturday-Sunday finish. Each of the past five years, the US. Open wrapped up on Monday, but only because of rain delays. Weather-related problems should become a thing of the past in the not-too-distant future: The US Tennis Association announced plans to build two retractable roofs. The aim is to have a cover for Arthur Ashe Stadium by the 2016 tournament. More money Another result of lobbying by top players is an increase in prize money at the majors – the US Open is raising its total payout about 35 per cent in 2013, to more than US$34 million (Dh124.8m). That includes $2.6m each to the men's and women's singles champions. A player who loses in the first round of singles will get $32,000. If either Nadal or Williams wins the title, the trophy would come with a check for $3.6m, because each earned a possible $1m bonus by finishing atop the standings from the US Open Series, which takes into account results on the North American hard-court circuit. Follow us

Andy Murray and Serena Williams lined up at this year's US Open

Defending champions and the other usual suspects headline a stellar cast at Flushing Meadows as the first round starts on Monday.