Rafael Nadal to return to No 1 for first time in three years after Roger Federer withdraws from Cincinnati Masters

The Swiss star, ranked No 3, is sidelined along with Andy Murray, Stan Wawrinka, Novak Djokovic and defending champion Marin Cilic leaving Nadal as the top-seeded player remaining

Rafael Nadal will return to world number one next week (Getty)

Rafa Nadal is set to return to world number one for the first time in three years after Roger Federer withdrew from the Cincinnati Masters with a back injury.

19-time major champion Federer tweaked his back during the Rogers Cup in Montreal, where he lost Sunday's final to Alexander Zverev.

The Swiss star, ranked No. 3, is sidelined along with No 1 Andy Murray, No 4 Stan Wawrinka, No 5 Novak Djokovic and defending champion and world number six Marin Cilic leaving Nadal as the top-seeded player remaining in the draw.

"It's just coincidence," he said. "We're not 20 years old any more. We're not playing all the weeks. It's part of our sport. I've been in their position lots of times. I've missed more events than the other players. It's part of the game. I wish them all a speedy recovery. We need them in the game. I hope they get back soon."

Federer's withdrawal means Nadal, who lost in the third round in Montreal, will return to top spot when new ATP rankings are released next week.

Nadal, who has spent 141 weeks at number one, is delighted to have climbed all the way back to the top of the world game.

"It's been tough to get back to No. 1," he said. "I'm happy to have the chance to be in that position.

"For me to be in that position is something very special. I have the passion and love for the game. That's why I'm able to be back in that position again."