New York: Rafael Nadal lacks one item to complete the changing of the guard in world tennis and the Spaniard could sew that up during his visit to New York City for the US Open.

Top-seeded Nadal has overtaken Roger Federer as world No. 1 and major championship favourite, and shown he can cut it on the grass by winning his second Wimbledon this year.

Now the stage is set for the heavy-hitting Mallorcan to lift the one major missing from his collection and prove he is a man for all seasons and courts by adding to his five French, two Wimbledons and Australian title for a career Grand Slam.

But Nadal, 24, has never reached the final of the bruising hardcourt test in Flushing Meadows, too often worn out by the last Slam of the season to thrive on the fast, rubberised concrete courts that have tested his troublesome knees.

Fit, well rested, hungry and armed with an improved volley to better shorten points, the left-hander looks poised for a breakthrough that could sweetly come in an Arthur Ashe Stadium finale against the second-seeded Federer.

“I am perfect mentally,” French and Wimbledon champion Nadal, winner of five events this year, said when he started his hardcourt build-up this month for an assault on the Open.

However, 29-year-old Federer is not about to hand the keys to New York over to Nadal without a fight.

The Swiss master, whose string of five successive US Open titles ended in a five-set loss to Juan Martin Del Potro of Argentina in last year’s final, revved his engines for another Flushing Meadows campaign by winning the run-up event in Cincinnati after reaching the final in Toronto.

“I didn’t play for six weeks after Wimbledon, I had a good vacation, spent some time in Switzerland with friends and family. From the mental side I have no problems whatsoever.

“Physically I feel the same thing. I feel as good as I can feel prior to a Grand Slam. I have no niggling injuries, no pain anywhere,” said Federer.

The men’s tournament at the National Tennis Center, of course, is not a two-man affair. Third seed Novak Djokovic of Serbia looms as a possible semi-finals hurdle for Federer, while fourth-seeded, in-form Briton Andy Murray could block Nadal’s path to the final.

Del Potro will not be on hand to defend due to a wrist injury, but competition should be intense on the men’s side.

“We can all play really well on the hardcourts. Murray has proven himself, so has Djokovic and so has Rafa. He’s won the Australian Open,” noted Federer. “Maybe the US Open is a bit faster, so you figure Rafa will struggle a bit more.”

While Djokovic has been battling health issues that might slow him down at the Open, Murray should have an added bounce to his step after beating Nadal and Federer to win in Toronto.

Murray, 23, is striving to become the first Briton to claim a grand slam crown since Fred Perry won the 1936 US title.

On the women’s side, line judges can relax, Serena Williams will not be gunning for her fourth US Open title.

Her withdrawal after slicing her foot on a piece of broken glass in July will allow match officials to breathe a little easier safe in the knowledge that there will no repeat of her foul-mouthed outburst of last year.

But rather than detract from the tournament, the American’s absence has unwittingly laid the foundations for one of the most wide-open women’s Grand Slam events in years.

The depth in women’s tennis has rarely been stronger and while Williams has been the dominant player for most of the past decade, there are many players willing to step up.

At least a dozen players hold genuine hopes of winning but the favourite with oddsmakers and sentimentalists is Belgian’s Kim Clijsters, a two-time winner in New York and this year’s second seed.

She won her first title in 2005, but it was her inspiring victory last year after taking a break to start a family that will be the enduring memory of her career.

After sweeping aside younger opponents to become just the second mother to win a Slam title, Clijsters celebrated by bringing her infant daughter on to centre court.

But time could be running out for Clijsters, who has won three WTA Tour events this season including Cincinnati earlier this month. She has spoken about her desire to have a second child, which she said will probably lead her into retirement, while a niggling hip injury has raised fitness concerns.

Denmark’s Caroline Wozniacki, who lost to Clijsters in last year’s final, returns as the top seed and looks to be hitting peak form at the right time.

She won in Montreal this month and if she wins her first Slam this year at the US Open could overtake Serena Williams as the world No. 1. Wozniacki was promoted to top seed after Serena withdrew and the draw did her no favours, putting her in the same quarter as two Russian former US Open champions, Maria Sharapova and Svetlana Kuznetsova.

Serbia’s Jelena Jankovic, a US Open finalist two years ago, looms as a possible semi-final opponent in a tricky top half of the draw, but it is Sharapova that poses the first big hurdle with the pair due to meet as early as the fourth round.

Sharapova, Clijsters and Kuznetsova are three of four players in the field who have already won the US Open. The other is Venus Williams, who won in 2000 and 2001.

India’s singles hopes begin their campaign Monday. While Sania Mirza will play Portugal’s Michelle Larcher de Brito, Somdev Dev Varman will take on Kevin Anderson, in their respective first round matches.