The king is not dead: Federer knows he's back in grand form

The leg and back injuries that troubled him during the grass-court season have cleared up, he has rediscovered the aggressive style that served him so well for so long and he has just won his first title for seven months. As Roger Federer heads for the US Open, which begins next Monday, the former world No 1 could hardly be in better shape going into the last Grand Slam tournament of the year.

You write off Federer at your peril. Although it remains to be seen how he will fare over a possible seven best-of-five set matches in New York, the manner of his victory in the Cincinnati Masters, secured with a hard-fought win over Mardy Fish in Sunday's final, suggested that the 29-year-old Swiss has put his recent difficulties behind him.

Having made such a good start to his 2010 campaign by winning the Australian Open, Federer aroused suspicions that he might be in long-term decline when his record-breaking run of 23 successive appearances in Grand Slam semi-finals ended in quarter-final defeats at both the French Open and Wimbledon. He left the All England Club bemoaning injuries, but the 16-times Grand Slam champion's failure to impose his game on opponents – particularly hard hitters like Robin Soderling and Tomas Berdych, his conquerors in Paris and at Wimbledon respectively – was arguably his greater problem.

Since Wimbledon, however, Federer has worked hard to regain form and fitness. Most significantly he has had a trial period with Paul Annacone, who used to coach Pete Sampras and Tim Henman. The fruits of their work have been evident in Federer's more positive play and in the greater variety on his serve, which was always one of his greatest strengths. In 42 service games in Cincinnati Federer was broken only once, while Fish forced just one break point in three sets.

"It's nice knowing that the hard work I put in during the off-season after Wimbledon has paid off right away," Federer said. "I know it's not all [down to] work from there, but I've been committed to this sport for many years. I think when you do that and give yourself chances over and over again, you'll break through by winning tournaments again.

"I came close a couple of times earlier in the season. I felt I should have won Halle. I could have won Madrid, but things didn't really work my way. I was maybe playing a little bit too passively. Now I'm taking it more to the opponents again. I'm happy that that's the right game plan right now."

Federer has not employed a permanent coach since parting company with Peter Lundgren seven years ago. Tony Roche and Jose Higueras both worked with him on a part-time basis, but in recent times he has toured with Severin Luthi, his Davis Cup captain, who is likely to remain a key member of his entourage.

Annacone, who is seeing out his current contract with the Lawn Tennis Association, spent some time with Federer in Switzerland after Wimbledon and was with him at the Toronto Masters, where the Swiss lost in the final to Andy Murray. The 47-year-old American was not in Cincinnati, but has been in regular telephone contact. Federer expects a long-term decision on their possible partnership to be made after the US Open.

As for his physical preparation, Federer said that he was enjoying the work with his long-term fitness trainer, Pierre Paganini, more than ever. "We've always looked for new ways to keep it interesting, even if the work-outs aren't sometimes the most fun," he said. "Today I know why I'm doing it, whereas as a teenager I never knew. I didn't know why a biceps exercise was good for my tennis, because I didn't get a five miles faster serve after that. Today I know exactly what I need to do."

Federer has a superb record in New York, where he won the title five time in succession before going down to Juan Martin del Potro in last year's final. The fast courts and balls suit his game perfectly. Federer expects Rafael Nadal, the world No 1, to be among his biggest challengers, along with Novak Djokovic and Murray, the men he beat in the 2007 and 2008 finals.

"We can all play really well on hard courts," Federer said. "Murray has proved himself, so has Djokovic on hard courts and so has Rafa. He's won the Australian Open. Maybe the US Open is a bit faster, so you figure Rafa will struggle a bit more. But if the draw goes his way, he'll be in the finals and have a crack to win the title, too. He knows how to win Slams. He's won all the other ones.

"I think it's going to be an interesting US Open. Many guys are playing well again. Murray didn't win a tournament for a long time, and he was able to win Toronto again, so that definitely makes him one of the favourites as well."

Federer added: "I have no lingering injuries, no problems whatsoever. I'm feeling healthy and fit, which was not the case during the grass-court season. That's a relief and I've been happy to start the American hard-court season so strongly."

Federer's year of highs and lows

January

Loses to Nikolay Davydenko in semi-finals of his first tournament of the season in Doha, but drops only two sets in winning Australian Open for fourth time (left), beating Andy Murray in the final of the tournament

Indian Wells and Miami

Goes out in early stages of both Masters hard-court events, losing to Marcos Baghdatis and Tomas Berdych

Clay-court season

Loses to Ernests Gulbis in second round in Rome Masters and to Albert Montanes in Estoril semi-finals before reaching Madrid Masters final, where he goes down to Rafael Nadal. Defeat to Robin Soderling in French Open quarter-finals ends his record run of 23 successive appearances in Grand Slam semi-finals

Grass-court season

Loses to Lleyton Hewitt in Halle final, only his second defeat in 77 matches on grass going back over eight years. Loses to Berdych in Wimbledon quarter-finals, ending his run of seven successive appearances in the final

North American hard-court season

Loses to Murray in Toronto Masters final in first appearance since Wimbledon before winning Cincinnati Masters to claim his first title for seven months

Sunday's victory in the Cincinnati Masters was Federer's first title since the Australian Open in January