SHANGHAI, China -- Roger Federer doesn't like hearing himself announced as the world's second-ranked player, and hopes his aching back doesn't hamper his pursuit of regaining top spot.
"I just don't like the ring of it," the defending champion said Saturday with a smile on the eve of the season-ending Masters Cup. "It sounds a bit awkward to me. It is a challenge to get back to No. 1."
Rafael Nadal is out of this event due to an aching knee but already has wrapped up the year-end top ranking. Federer is therefore looking at Shanghai as a chance to build some momentum for 2009, with the Australian Open in January his first chance to tie Pete Sampras' record of 14 Grand Slam titles after winning the U.S. Open in September.
"I haven't been thinking about it much," Federer said. "Once I go on vacation, I'll have plenty of time for that."
The biggest question is his back. Federer withdrew from the Paris Masters last week. He has been getting daily treatment and taking painkillers.
"It's way better than last Friday," Federer said as the eight Masters Cup players, dressed in matching gray suits and black silk shirts, met with reporters. "I've been able to practice without pain."
Still, he doesn't know quite what to expect when he faces France's Gilles Simon on Monday in round-robin play at the tournament for the world's top eight.
"I'm not sure because I haven't been pushing it to the very limit," the Swiss star said, adding that he's worried he could tweak his back again. "It just needs as much time as possible."
Still, he declared himself the favorite, an opinion echoed by other players, even though some of them have been in better form in recent weeks.
"I'm here to win," Federer said. "I'm not here just to participate."
Jo-Wilfried Tsonga, one of four players making his Masters Cup debut, was the last man to clinch a spot in the elite field, winning in Paris.
"For me, it's just amazing; it's a dream," said Tsonga, who plays fourth-ranked Nikolay Davydenko on Sunday after No. 3 Novak Djokovic of Serbia opens the event against Juan Martin Del Potro. The Argentine earlier in the year won 23 straight matches and four consecutive tournaments.
Tsonga, who thinks the indoor Qi Zhong Tennis Center will suit his game, has jumped in the ratings despite missing three months recuperating from knee surgery -- a break that may have worked in his favor as other players wind down the long tennis season.
