(Paul Chiasson/The Canadian Press via AP). Roger Federer, of Switzerland, wipes his brow during his final match against Alexander Zverev, of Germany, at the Rogers Cup tennis tournament in Montreal, Sunday, Aug. 13, 2017.
MASON, Ohio (AP) - Wimbledon champion Roger Federer has withdrawn from the Western & Southern Open, which he has won seven times.
Tournament officials announced Federer's withdrawal on Monday, the first full day of matches at the event in Cincinnati.
The 19-time major champion says he "tweaked" his back last week at the Rogers Cup, where he lost Sunday to Alexander Zverev in the final.
The Swiss star, No. 3 in the ATP Tour rankings, becomes the fifth of the top six players to skip Cincinnati because of injuries. He joins top-ranked Andy Murray, No. 4 Stan Wawrinka, fifth-ranked Novak Djokovic and sixth-ranked Marin Cilic, the defending champion.
Federer's withdrawal means Rafael Nadal will return to No. 1 when new ATP rankings are released on Aug. 21. The Spaniard will be No. 1 for the first time since July 6, 2014.
Nadal has spent 141 weeks as the men's No. 1 player.
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