Roger Federer has withdrawn from the Madrid Masters because of a back injury.

The third-ranked Federer said Monday that he was hurt in practice during the weekend and didn't want to take any chances aggravating the injury.

Federer was coming of a knee injury after the Australian Open which sidelined the Swiss player for about two months.

The 35-year-old Federer, the winner in Madrid in 2012, had been a late addition to the field this week. The tournament was not originally on his schedule, but the former No. 1 decided to include it as part of his preparations for the French Open in three weeks.