MASON, Ohio (AP)—Roger Federer usually feels good when he arrives in Cincinnati for a tournament he has won more times than anyone else. This week, not so much.
Federer is trying to reconstruct his game and keep his back healthy at the Western & Southern Open, a Masters series tournament he won for an unprecedented fifth time last year. He likes the fast blue surface and the quiet time away from the courts.
Throughout his career, he's used the tournament as a springboard to the U.S. Open. He's in more of a rebuilding mode entering the event, which opened Sunday with two men's matches.
After a stunning loss second-round loss at Wimbledon, Federer's had surprising exits in two other tournaments to lower-ranked players. He's also been bothered by a bad back.
''But now I'm fit again and I'm mentally motivated, which is very important at this part of the year right now,'' Federer said.
A couple of over-30 Swiss stars will get the attention this week.
Martina Hingis is playing doubles as part of her comeback after a six-year retirement from the WTA Tour. Hingis, who turns 33 next month, is teaming with Slovakia's Daniela Hantuchova.
It's their third tournament together. They lost their second match at Carlsbad and were knocked out in the second round in Toronto on Thursday. Hingis was inducted into the International Tennis Hall of Fame last month. She's the first player to compete in Cincinnati as a Hall of Famer.
Top-ranked Serena Williams will be fresh off her third Rogers Cup title. She beat unseeded Romanian Sorana Cirstea 6-2, 6-0 Sunday in Toronto for her eighth WTA title of the year.
No. 1 Novak Djokovic is trying for his first win in Cincinnati after reaching the finals and losing four times, including last year to Federer.
Federer arrived in Cincinnati earlier than usual after skipping the Rogers Cup in Montreal last week to work on his game and his health. It's been a rough summer for Federer, who turned 32 last week.
He suffered a second-round lost at Wimbledon, beaten by 116th-ranked Sergiy Stakhovsky. His earliest exit from a Grand Slam event since 2003 ended a streak of reaching the quarterfinals in 36 straight major tournaments.
The upsets weren't over.
Federer decided to play in a couple of clay-court tournaments. He lost to 114th-ranked qualifier Federico Delbonis in the semifinals at Hamburg and was beaten by 55th-ranked Daniel Brands in his opening match at Gstaad, Switzerland.
Federer has been experimenting with a larger racket - he plans to use it in Cincinnati - and trying to overcome a back injury.
''I was ready to get over the Wimbledon loss as quick as I could, which I did,'' Federer said. ''I took a short break and then started practicing extremely hard and things were great.
''I tested rackets and was ready to go to Hamburg and Gstaad and really play tournaments I really enjoy playing, but I couldn't enjoy them in the end because I just had too many problems with my back and my body.''
Normally, he'd be trying to fine-tune his game and build confidence this week heading into the U.S. Open. He's got a lot on his to-do list this year.
''Getting my game back together, really, and my body,'' Federer said. ''So far so good. I'm motivated. I'm feeling better and I am entering Cincinnati with a good mindset. Right now, it's key.
''Now if I could win more matches, that would be good because I did win a title here, and that makes me think I can do something great here. As at every other event, you always struggle in the first round.''