A disappointing year ended with another loss for Roger Federer. However, after a mini-resurgence late in the season, though, the former top-ranked men's player has reason to believe he can still compete with the best again next year.

The 32-year-old Federer lost in straight sets to rival Rafael Nadal in the semifinals of the ATP World Tour Finals on Sunday, ending a season in which he has slipped to No. 7 in the rankings and lost in the second round of Wimbledon and the fourth round at the U.S. Open.

But he managed to qualify for the ATP finals after a string of good results over the past few months that, in his opinion, bode well for 2014.

"I think something is possible for next year," Federer said after his 7-5, 6-3 defeat to Nadal, his first loss to the Spaniard on an indoor hard court. "I think it was a stronger finish than I thought it was going to be in Basel, Paris and London. I'm more positive now looking ahead than I would have been a few months ago, when I wasn't quite sure what to expect after the U.S. Open."

The 17-time Grand Slam winner, who finished 2013 with a modest record of 45-17, insisted he has reached a point in his career where his ranking is secondary, as long as he still feels capable of winning big matches and big tournaments.

"It's important to stay within a certain ranking," Federer said. "But after that I need to make sure I stay competitive, I can hang with the best, and particularly beat the best."

That has not often been the case this year, with Federer claiming only four wins over top-10 opponents — beating Juan Martin del Potro twice, Jo-Wilfried Tsonga and Richard Gasquet — and regularly losing to unseeded opponents. He won his sole title at a grass-court tournament in Germany in June.

But the Swiss star was reassured by the fact that his body held up well over the last three weeks and seems convinced he can take fewer breaks next year.

"What I learned is that I can play three weeks pretty easily," he said. "I played a lot of matches as of late, a lot of three setters, a lot of tennis. From that standpoint, that's very satisfying, knowing that the body can do it, the mind can do it, life allows it to happen. I'm happy that I have that option, as well, that I know I can play three weeks in a row because I remember (Andre) Agassi didn't do that at all any more toward the end of his career. He used to play one, maybe two, he would always pull out the third week if there was something planned."

Federer remained vague about the tournaments he intends to play in 2014, saying his schedule will be geared toward peaking at the four majors.

"Clearly Grand Slams are going to be part of my highlights, hoping to sort of make sure I play my best there with some selective other events that I consider important to me, some of the Masters 1000s," he said. "Then hopefully I have something left for the World Tour Finals at the end of next year because that's clearly a goal."

Saying that tennis his part of his "DNA," Federer also brushed off speculation that he might be tempted by retirement. He has previously stated the 2016 Olympics is a possible goal.

"The thing is that when you stop, you're still so young that why stop so early? Why just walk away from it because, I mean, I have many other things to do in my life than play tennis, but because I can still choose, I pick to play," he said. "As long as I have this choice, I'll keep on playing."