THERE is something vaguely improper about putting an age on Roger Federer, almost like plastering a price tag on a Van Gogh.

His age, too, is almost irrelevant in his present state of irrepressible power. Federer, at 33, is making his 13th consecutive appearance at the end of year finals and he has given himself an excellent chance of competing for a seventh title by beating Kei Nishikori of Japan 6-3, 6-2 in one hour and nine minutes.

Federer always comes to these championships with both motivation and residual strength despite an arduous campaign. There may be niggles for the 17-time grand slam champion but it was Nishikori who needed treatment on court for a wrist injury.

Recording a second straight-sets win in the tournament, Federer could afford to be reflective in the post-match press conference.

He was even prepared to consider the dimming of the light on his career, though he believes to the very tip of his sponsored trainers that he has another grand slam to attach to his record haul.

However, pressed on whether Nishikori represented a generation that was ready to take over from what is still called the Big Four, Federer maintained that the golden generation of tennis still had a few years in it.

"It is going to remain good for a while now because Novak [Djokovic] and Rafa [Nadal] and [Andy] Murray, they're way younger than I am. They're going to be around for a while," he said.

Of course, while Federer has spent the season taking the lead in tour match wins (70), Murray has been recovering from back surgery and Nadal has been succumbing to appendicitis. This physical resilience is just one of the components that makes Federer on course to become the oldest player to finish the year in the top two in the rankings.

He addressed the strata below the Big Four by saying: "The next generation - Nishikori, [Milos] Raonic, [Grigor] Dimitrov . . . I think they're only going to get better and hopefully eventually they're going to win the bigger tournaments, like the 1000s, these kinds of events, as well, so forth, then the slams."

However, he added: "The next generation is the one I'm curious about to see, which is sort of [who is the] 16 to 17-year-old to 20-year-old who is going to make the break in the next few years. It seems to be very hard to do as of late, but there is some talent there."

Federer believed that tennis was in "exciting times", adding: "The usual guys that everybody knows for a long time still enjoy the game and like to be out on centre court, as well, accepting the challenge of the young guys."