Roger Federer of Switzerland celebrates after defeating Mardy Fish of the U.S. during their singles tennis match at the ATP World Tour Finals in the O2 Arena in London November 24, 2011. [Photo/Agencies]

Roger Federer still looked as fresh as a daisy as he polished off Mardy Fish to post a 100 percent record in the group stage of the ATP World Tour Finals on Thursday which is more than can be said for most of his main rivals.

No wonder then that arguably the greatest player ever to wield a tennis racket is perfectly happy with the schedule and dismissed the distant prospect of a players' strike as "nonsense".

Andy Murray, the man who jumped above Federer to third in the world rankings this year, pulled out of the London showpiece with a groin injury, world number one Novak Djokovic looks jaded after struggling with a shoulder problem and great rival Rafa Nadal has lacked spark for a few months.

At 30, the Swiss 16-times champion is the oldest of the nine players at the season-ender in London this year, but judging by the way he is ending the season his sell-by date is clearly some way off and, for him at least, the crowded nature of the ATP Tour calendar is not a major issue.

Murray sparked talk of a strike in September when said those organising the Tour were not sympathetic to the demands on the players' bodies, although the Scot later said there had never been a meeting to propose any kind of boycott.

Meanwhile Federer, who ended the year without a grand slam title for the first time since 2002, rolled past 800 Tour wins and claimed back-to-back titles in Basel and Paris. On Tuesday he thrashed Nadal for the loss of three games and is favourite to win the season-ender for a record sixth time.

Asked about the gruelling season and talk of strikes, Federer dismissed them out of hand.

"Next year's season is going to be shortened by two weeks," he told reporters after a 6-1 3-6 6-3 defeat of Fish -- a useful warm-up for Saturday's semi-finals.

"That's I think as much as we can squeeze it really because otherwise a lot of tournaments would have to go or we would have four tournaments the same week, which I don't think is a very smart idea, to be honest, for the game.

"Yeah, (a strike) was brought up a few months ago, the whole boycott thing. It's nonsense. It's not going to happen any time soon. Things are good right now, so I don't see a reason why we should just boycott. There's absolutely no reason for it."

Others may beg to differ, even if next year's finish will be in early November rather than nearly into December.

Nadal, who took time off after Shanghai spoke of his crowded schedule this week while Djokovic, the outstanding player of the year and winner of three of the four majors this season, said "it was a long discussion" when asked his opinion following a lame defeat by David Ferrer on Wednesday.

"The season's always been long, tough and gruelling," Federer said. "Back in the day they used to play singles and doubles. Now maybe it's got more physical so we play mostly only singles. But I've played 10 years straight now I guess 60-plus matches, if not even 90 at times.

"I think it's about how you manage your schedule. It's really only the final day that we'll really know who's tired and who's not."