Roger Federer wasn't among those finalists

The tournament has only just ended but, as always, we are already looking back on it fondly.

The crowd, the energy and the constant noise have been replaced by silence, focus and emptiness. Only the finalists remain.

And, for once, Roger Federer wasn't among those finalists; he fell in the semi-finals, beaten by Novak Djokovic after missing two match points.

It's a year now since the Swiss player stopped being totally convincing. We were used to way better form from him. He is no longer steady and consistent enough during his matches.

Yet we were kind of reassured by his summer. He was playing so much better. His matches against Djokovic and Tomas Berdych in Toronto brought the 'old Roger' back: focused from the first to the last point, crushing, offensive.

His footwork was again in shape and his whole game was benefiting from it, and so we had huge ambitions for him in New York.

But in the US Open he didn't display any of this. Moving too slow, not really inspired in his attacking game and lacking aggression, Roger has once again showed a face that we're starting to get used to.

And so here are the questions that are now surfacing. Are those losses evidence of the fading of King Federer? Is Roger the victim of a motivational crisis after the birth of his daughters - but also after his French Open and Wimbledon double in 2009? Is the Swiss player injured?

He has already admitted that he had been playing many matches with an injured back. If we're paying a lot of attention to the way he played in New York, to the way he moved, we could easily believe it.

Anyway, this Federer isn't the big champion we know he is. He will have to solve, and fast, all his issues, mentally and physically.

Otherwise, he won't be able to win Grand Slams again; not with this level of play, even if it's enough for now to get to the quarter- or semi-finals.

On the other hand, Rafael Nadal is having an amazingly successful season, with three Grand Slams and three Masters 1000 under his belt. He only failed at the Australian Open, pulling out injured during his match against Andy Murray - but having already played great tennis.

Rafa is bossing the whole field and, most impressively of all, he's doing it on every surface.

He keeps improving on his serve and his backhand. The intensity he can display and his focus make him a rare kind of player. I've never seen anyone able to hit each ball from January 1 to December 31 with the same power and will to succeed. If he can stay healthy, he could prevent Federer from winning any further majors.

Novak Djokovic has been the positive story of this summer.

Struggling a lot during the first part of the year, he prepared perfectly for the US Open. He worked so hard and arrived physically fit, which is key for him.

His serve is mainly back, a problem solved with Todd Martin's input, and finally his forehand is a weapon again and helps him to dictate the game when he needs to.

He had the good fortune to meet a not-so-inspired Federer in this semi-final though. For sure Nole is on the right path but if he wants to win another Grand Slam, confronted by those two giants, Federer and Nadal, it seems like the road is still pretty long.

Disillusion is the most suited word for what happened, again, to Andy Murray. He's really having a disappointing season.

He was seen as the number one outsider following his victory in Toronto where he beat Nadal and Federer - but ended up falling in the third round to Stanislas Wawrinka.

The Scotsman is still capable of the best as much as he is of the worst. That has been his main issue for two years now. He can't find a way to maintain a steady level and it's still really hard to find a guideline in his game.

The amazing talent is still there, but he hasn't succeeded in finding his own style whereas the best players are always using the same weapons from one match to another, finding intensity and confidence.

As far as Tomas Berdych goes, he has improved a lot this year and he's way more consistent than he used to be. He reached the final at Wimbledon and the semi-final of the French Open.

Yet, as I've already said, I still feel he's not at the same level as the top players. His game is really clean but maybe too predictable and lacking of diversity. At the US Open, Michael Lodra and his unique way of playing knocked him out in straight sets.

A word finally on Marcos Baghdatis and David Nalbandian, who also didn't confirm their return to the top level. They are often brilliant in less important events, but it's the Grand Slams that are career-makers. Seeing them back in shape is encouraging - but we'll have to keep an eye on them in the months to come.