Roger Federer played Andy Murray at the Western & Southern Open, in Mason, OH, Saturday, Aug. 22, 2015. GREG LYNCH / STAFF

Federer pulls out of Western & Southern Open in Mason with injury

Seven-time champion Roger Federer has pulled out of the Western & Southern Open with a back injury.

“I am very sorry to pull out of the Western & Southern Open as I always enjoy playing here,” said Federer, who has won a pair of Grand Slams — Australian Open, Wimbledon — this year. “Cincinnati has some of the best fans in the world and I am sorry I will miss them. Unfortunately, I tweaked my back in Montreal and I need to rest this week.”

Federer’s withdrawal means Rafael Nadal will return to No. 1 in the world rankings when new rankings are released next Monday for the first time since July 6, 2014.

The W&S Open at the Lindner Family Tennis Center in Mason is one of only five non-Grand Slam events that feature the top men’s and women’s players in the world.