By Martyn Herman
LONDON (Reuters) - At 29, Roger Federer will be the elder statesman at the ATP World Tour finals which start in London's Docklands on Sunday but the Swiss is not about to start fretting about the passing years.
In fact, the 16-times grand slam champion is adamant the demands of the muscular, super athletic, power-based game that now dominates tennis have made the top echelons of the game a no-go zone for the new kids on the block.
A keen observer of the sport's trends, Federer said on Friday that there were no teenagers inside the world's top 100 and suggested you would not find a player younger than 22 with a double digit ranking.
Just like his artistic game which often flies in the face of the baseline warfare played by so many of his rivals, Federer's observation was spot on, as a trawl through the ATP's latest ranking list showed.
You have to scroll down to 114th ranked Bulgarian Grigor Dimitrov -- a player often compared to Federer -- before you find a teenager cutting it at the sharp end of men's tennis.
It is a far cry from the day when Federer reached the top 100 when he was 18, current world number one Rafael Nadal did it when he was 17 and Andy Roddick charged into the world's top 20 before his teenage years were over.
"Promising newcomers? Not a whole lot really," Federer told reporters when asked where the next generation of possible grand slam champions were.
"I was asking myself that same question. It's quite surprising for me because when I was coming up there was (Lleyton) Hewitt and (Marat) Safin and Roddick and (Juan Carlos) Ferrero and (Tommy) Haas. They were all in the top 100 as teenagers.
"It's become more physical and more mental and maybe they need longer to break through now," said Federer, the oldest of the world's top eight players contesting the season's finale at London's O2 Arena.
"It can be a good or bad thing depending on where you look at it from. But I'm always excited to see who is coming up."
"The sport has become a bit tougher, it's much more physical than say 10 years ago," Soderling, who overpowered Federer in the French Open quarter-finals this year and plays Andy Murray in the opening singles at the ATP World Tour finals, told Reuters on Friday.
"I played my first ATP final when I was 18 or 19 but it was tough to cope with the demands week in week out."
"It's a tough ask of an 18 or 19-year-old to play the kind of tennis we have today 40 weeks a year.
"I weigh more than I used to and everyone is now bigger and stronger making it so much harder for younger players."
Roddick said qualifying for his eighth ATP Finals despite an injury-hit year had been one of his most satisfying achievements but hoped the ATP would help the leading players by agreeing to shorten the calendar.
"I honestly believe the powers that be are working toward giving us at least some relief, even if it's not perfect," he said. "Because it's getting tougher.
(Editing by Alison Wildey)