Roger Federer cautious but confident heading into ATP World Tour Finals

Roger Federer said he hopes to show more consistency at the ATP World Tour Finals. (Clive Brunskill/Getty Images)

LONDON -- Roger Federer sounded a little under the weather as he addressed the media in advance of the ATP World Tour Finals on Sunday. But after two weeks of quality play, he says he comes into his 12th straight World Tour Finals riding a wave of confidence.

"I'm happy with my game," Federer told reporters. "My confidence is back again and that can carry you a really long way. So that's good."

A six-time champion of the season-ending ATP event, Federer didn't dismiss any doubts about his current fatigue level. Having made the Swiss Indoors final and Paris Masters semifinals, the 32-year-old Federer played nine matches in 12 days, including five three-setters. He'll have just two days of rest before his first match, against Novak Djokovic on Tuesday night.

"It's been a lot of tennis, no doubt about it," he said. "I was hoping for that problem to occur. So I'm happy it's gone this way, to play a lot of matches and won a lot now these past couple of weeks. But these two days now are crucial."

Federer admitted at the Swiss Indoors that he regretted playing through injury during two crucial moments of the season. His back flared up in Indian Wells and then again during an impromptu two-tournament clay swing after his shocking second-round loss at Wimbledon. Now that he's focused in on a reason for his fitness problems that led to his erratic results, the questions as to why and how his substandard year came together have begun to dissipate.

"You start doing so much work just to be in decent shape and then still you're not feeling great," he said. "It just becomes quite frustrating and a little disappointing. But then again, I always see the glass half full. I'm a very positive thinker. So every time for me it was important to exactly understand why I had the results I had, why I played the way I did and why I'm feeling the way I'm feeling. Once you get a grip on that, it's OK; it's something I have no problem to accept. Then it's important to be able to move on and you have a plan."

His timing couldn't be any better. Now ranked No. 6, Federer is going for his second title of the season this week. He's been drawn into a group with Djokovic, Juan Martin del Potro and Richard Gasquet. Given his up-and-down year and the amount of matches he's played over the last two weeks, Federer still remains cautious about his expectations this week.

"I know that the year has been a bit more difficult," he said. "Most of the time I was just focusing on myself to get things right in my life, with my back and so forth, and now finally that I did I feel like it's coming together at the right time for me. But [this season] has a different feel. It hasn't been as consistent, as good, as solid as it has been in previous years. So I'm maybe still a little bit -- I don't want to say insecure -- but unsure about how high is my level of play even though it has been good these last three weeks."