Roger Federer usually feels good when he arrives in Cincinnati for a tournament he has won more times than anyone else. Not so much this time.

Federer is trying to reconstruct his game and keep his back healthy this week at the Western & Southern Open, a Masters series tournament he has won an unprecedented five times, including last year.

The Swiss star suffered a stunning loss to a player ranked 116th in the world during the second round at Wimbledon. He's switched to a bigger racket, gotten upset in other tournaments and struggled through a sore back. He dropped out of the Rogers Cup in Montreal last week.

Martina Hingis continues her comeback in doubles at the tournament, which began Sunday afternoon with two men's matches.