Federer withdraws from Cincinnati; Nadal to become new No. 1

MASON, Ohio — Wimbledon champion Roger Federer has withdrawn from the Western & Southern Open, which he has won seven times.Tournament officials announced Federer's withdrawal on Monday, the first full day of matches at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 b