Augusta (United States) (AFP) - South Africa's Louis Oosthuizen, the 2010 British Open winner, withdrew from the Masters on Friday with an unspecified injury.
World number 14 Oosthuizen was a playing partner of Tiger Woods, who will continue his remarkable return from severe leg injuries in a car crash 14 months ago alongside only Chile's Joaquin Niemann at 1:41 p.m.(1741 GMT).
Oosthuizen, 39, opened with a four-over par 76 on Thursday and was grabbing his balky back at times during the first round.
He joins England's Paul Casey as having withdrawn from the event.Casey pulled out before Thursday's start, but would have been in the group just ahead of Woods.
Oosthuizen is a six-time major runner-up, including seconds at last year's US Open and PGA Championship, and shared third in last year's British Open.He was also second at the 2012 Masters.
