British Open champion Darren Clarke is facing a race against time to shrug off a groin strain ahead of next week's Masters.
Clarke limped off the course at the Shell Houston Open on Friday, having strained a groin muscle during his second round of 71 which put him 1-under for the tournament.
The Northern Irishman felt the injury while completing his rain-delayed first round on Friday and played on through the pain barrier to complete his second.
''It's a really long walk around this golf course and I could have come in after three to four holes this morning but it seemed okay when I finished my first round today but it's just got progressively worse in the second round,'' he said.
''I wanted to keep going, keep going and keep going as I need to play all four rounds before the Masters.''
Clarke was one shot outside the projected cut and a weekend away from the course may be a good thing with the Masters beginning next Thursday.
It was suggested by Clarke's personal trainer he attend a local doctor to assess the full extent of his injury but Clarke declined.
''I've had these type of injuries in the past and there's not much you can do but rest,'' said Clarke.
Clarke earned a five -year Augusta National exemption in winning last year's British Open and he will be competing in the event for the first time since 2007, when he missed the cut.
