CARNOUSTIE, Scotland, July 17 - Twice former U.S. Masters champion Jose Maria Olazabal has pulled out of the British Open with a knee injury, organisers said on Tuesday.

The Spaniard was already doubtful for the event, which starts on Thursday, after withdrawing from last week's Scottish Open because of the problem with his left knee.

He had been scheduled to tee off with Briton Graeme McDowell and U.S. Masters champion Zach Johnson and his place will be taken by American Tom Pernice Jr.

The 41-year-old Spaniard, who won the Masters in 1994 and 1999, withdrew from the 1995 Ryder Cup with a foot problem.

He was eventually diagnosed with rheumatoid polyarthritis in three joints of his right foot and two in his left.

Olazabal returned to golf after an 18-month absence during which he could often not even get out of bed.