Roger Federer has heard the talk about his supposed decline before and the world number two finds it hard to take the suggestion seriously.

The record 16-times Grand Slam winner failed to get beyond the quarter-finals at the French Open and Wimbledon this year and with the last Grand Slam of the season, the US Open, on the horizon, talk has turned to whether the Swiss is fading.

Federer, who lost to Andy Murray in last week's final in Toronto, appears to find the idea ridiculous.

"I had a wonderful summer last year with (winning) the French Open and Wimbledon, which wasn't case this year.

"But last year after the Australian Open when I lost against Nadal, people were also talking about how I was on a huge decline. I cried on center court at the Australian Open, which was a big tragedy for many people," he told reporters.

"Nobody ever believed I would come back. I won two Slams and played the finals of the US Open and won the Australian Open, so then everything changes and you don't win the French or Wimbledon, and things are all bad again.

"So it moves very quickly. I know the rules and how it all works," he said.

Federer said that in the current era - with four outstanding players at the top of the rankings and others, such as Robin Soderling and Tomas Berdych closing in - people had better get used to keen competition.

"(You) can't win them all. I always knew that, so I was very shocked and surprised at how dominant I was and how well I played for so many years. And still today I'm hanging with the top and I've got chances, and already won a Slam again this year. I have a chance to win a second one and maybe the World Championships at the end of the year.

"There's still a lot to play for. But usually if you stay the same, you will move down. That's never something I was content with," he said.

Federer, whose semi-final win over Novak Djokovic last week regained second spot in the world from the Serb, says he has a very simple measurement for how well he is doing.

"For me, it's important that I'm happy with my game...I'm very happy with how I played in Toronto.

"I fought hard and I was able to turn it around a bit and get those close matches going my way. Now we're gonna be on this kind of (hard court) surface for eight months, so I think this is a very important start for me, playing well on the hardcourts again," he said.