Roger Federer hopes to mark the 10th anniversary of his first US Open title with a sixth triumph in New York and become the oldest Grand Slam champion in more than 40 years.

In an astonishing reversal of fortunes, the 33-year-old, written off as a relic of the game when he slipped to a fourth-round loss to Tommy Robredo 12 months ago, finds himself perfectly positioned to win a staggering 18th major.

Buoyed by claiming a sixth Cincinnati title - his 80th career crown - and with long-time rival Rafael Nadal again sidelined with injury, the Swiss is relishing the twilight of his career.

His last-16 loss to Robredo in 2013 in New York meant it was the first year since 2002 that he had failed to make a Grand Slam final. The defeat also marked the first time in 10 years he had not made at least the last-eight at Flushing Meadows.

Suddenly, his five consecutive US Open titles from 2004-2008 appeared a detail in history and his 17th and most recent major success - the 2012 Wimbledon title - looked certain to be his last.

But the Swiss never doubted his ability to remain a force in the sport and he goes into his 15th US Open with his unwavering confidence justified.

There were hints of a revival at Wimbledon in July where he was defeated in five sets by world No 1 Novak Djokovic.

Since then, he has been runner-up at Toronto and champion in Cincinnati and the problems of 2013, when he was hampered by a back injury, are now distant memories.

"I was scared to have another setback and so it was just not as clear-cut and simple as it is this year," said second-seeded Federer, who faces Australia's Marinko Matosevic in the first round of what will be his 64th consecutive Grand Slam.

"This year I played a lot of good matches. Not just Toronto and Cincinnati, but really from the first week on I have always played really nice tennis.

"You almost forget how to lose a point and confidence rises. You're back to winning ways again and everything seems so simple. I'm looking forward to this tournament because I really feel like I can play a great tournament. I hope I can show that on the court this year."

Djokovic, the 2011 champion and who has featured in the past four finals, heads into the US Open with dispiriting third-round losses in Toronto and Cincinnati.

The 27-year-old Serb, recently married, has also had to bat back accusations that he is distracted by impending fatherhood.

"I wanted to do better in Canada and Cincinnati. Unfortunately, I wasn't even close to my best. But, you know, a lot of things happened in the last two months and it was very emotional period," said Djokovic, who plays Argentina's Diego Schwartzman in Monday's first round.

"I just felt a little bit flat on the court. I wasn't managing to find that intensity and the perfect mindset."

Despite recent hiccups, Djokovic's record at all the majors is impressive - the last time he failed to make at least the quarterfinals of a Grand Slam was at the 2009 French Open.

The odds on Djokovic and Federer meeting in the Sept 8 final were shortened when defending champion Nadal was forced to withdraw with a right wrist injury.

Andy Murray, the 2012 champion, has not reached a final of any description since his historic 2013 Wimbledon triumph.

Now down at nine in the world, the 27-year-old has not got beyond the quarterfinals of any tournament since his morale-sapping semifinal loss to Nadal at the French Open where the Spaniard allowed him just six games.

"This year would be the best prepared I have been coming into a Slam. I got a great training block over in Miami done, so physically I'm where I would want to be. My body is pain free, which is good," said Murray, whose first-round foe is Robin Haase of the Netherlands.

With 2009 champion Juan Martin del Potro still sidelined by injury, the much-vaunted next generation will get another opportunity to shine.

But they remain works in progress.

Canada's Milos Raonic, the world No 6, was a semifinalist at Wimbledon and Cincinnati, where he was swept aside in straight sets on both occasions by Federer.

Fellow 23-year-old Grigor Dimitrov, the world No 8, has three titles to his name in 2014 but lost out to Djokovic in the Wimbledon semifinals.