Roger Federer training in Dubai, still testing larger racket head frames

Roger Federer reached the semifinals of the ATP World Tour Finals at the end of the season. (Glyn Kirk/AFP/Getty Images)

In an interview with his sponsor Credit Suisse Bank, Roger Federer revealed that he has resumed testing larger rackets. Federer experimented with a 98-square-inch frame for two post-Wimbledon clay-court tournaments but switched back to his usual 90-square-inch head for the rest of the season.

Asked about testing rackets with bigger heads again, Federer said: "I will, for sure. Because this summer's tests don't tell us much because I wasn't able to play properly in Hamburg and Gstaad because of my back problems."

Federer has skipped his usual offseason exhibitions in favor of a full training block in Dubai to prepare for the 2014 season.

"I can see no reason why I shouldn't play better again in 2014, and have some great wins," Federer said. "I have still got some major goals, because I certainly haven't forgotten how to play tennis; after all, I was still number one in the fall of 2012, and at the end of the season, once my back was better, my results also improved. I reached the final in Basel and the semi-finals at Paris-Bercy and the World Tour Finals, and beat top-10 players without playing my best tennis. If my serve or my forehand had been a bit more solid, the results could have been much better."

Last month, Novak Djokovic blamed Federer's movement for his subpar season. Federer sustained a back injury in the spring that limited his training schedule, and he struggled through the season to get fit.

"What he says is true," Federer said of Djokovic's comments. "But it would also be strange if I could move wonderfully and at my best after a year when I couldn't train enough and in between times lost quite a bit of my self-confidence. I don't feel that I am as fast as in my best years, either. But despite that I can still compete with the best. That makes me feel positive."

Federer split from coach Paul Annacone after the U.S. Open and may not hire a new coach. He says he's comfortable with the team he has, and his positive end to the season has injected some much-needed energy into his training.