Twice US Masters winner and 2012 European Ryder Cup captain Jose Maria Olazabal pulled out of the PGA Championship on Thursday because of a back injury.

The 45-year-old Spaniard was five-over-par through seven holes when he was forced to withdraw from the Wentworth event.

“This is the European Tour’s flagship event, a huge field, a place I love, but unfortunately I couldn’t keep on playing,” Olazabal told reporters.

“They (the physios) can’t really figure out what the problem is at the moment. I’m going to get a scan and some treatment done and see if we can get some more information.”

Olazabal said the injury first flared up on the practice range.

“I started hitting balls before teeing off. I started feeling it with the three-wood and then hit a few drivers and it got a little worse,” he explained.

“Obviously it didn’t get any better as we kept on playing.”

Briton Paul Waring (wrist injury) and Dutchman Robert-Jan Derksen (rib) also pulled out of the tournament on Thursday.