Graeme McDowell has been forced to withdraw from the Valero Texas Open in San Antonio with an ankle injury . The Northern Irishman suffered the problem during practice on Wednesday and , although he managed to play his opening nine holes on Thursday . After pulling out of the tournament he has set his sights on getting fit for the Masters at Augusta National from April 9 . Graeme McDowell withdrew after his opening nine holes of the Valero Texas Open due to an ankle injury . The Northern Irishman picked up the injury in practice before deciding he could n't go on at five over par . McDowell , tweeted : 'Apologies to everyone at @ valerotxopen for my withdrawal . Strained my lower left leg/ankle area practicing y/day and played with heavy strapping on it in the pro am and this morning . 'With The Masters upcoming I decided that getting fit is imperative . Do n't like WDs . 'The week here at @ valerotxopen had everything I wanted . Great people and great course . Disappointed this has happened . Thanks to everyone . ' McDowell , who won the US Open in 2010 , was five over at the Valero Texas Open when he withdrew , having started on the back nine . McDowell has now turned his focus to being in the best condition possible for The Masters on April 9 . After completing only the back nine , he said : 'With The Masters upcoming I decided getting fit is imperative ' American Matt Kuchar ground out a level-par 72 that he described as 'amazing ' to share the early first-round lead in San Antonio , where the players struggled in gusting winds on Thursday . World No 14 Kuchar , a seven-times winner on the PGA Tour , needed ' a lot of luck ' as he mixed four birdies with four bogeys on the challenging layout at the TPC San Antonio to end the round level with compatriot Cameron Percy . Former world No 2 Jim Furyk battled to a 76 while US Open champion Martin Kaymer of Germany ballooned to an 82 in sustained winds of 30 miles per hour ( 48 km per hour ) that gusted up to 40mph . ' I was giving it all I could on the last hole , ' Kuchar , 36 , told Golf Channel after bogeying his final hole , the par-four ninth . ' I was one under with one to go and hoping that I could bring it in under par . Matt Kuchar battled swirling winds to grind out a level-par 72 for the lead early in the first round . Kuchar said he needed ' a lot of luck ' as he mixed four birdies with four bogeys on day one . 'But even par is still an amazing day . This was about as challenging of conditions as I can remember facing . This course is hard without wind and you 've really got to drive it well . Then you throw in 30mph winds and what can happen . 'It took a lot of luck for me . I had a number of things kind of go my way . I was able to hit some great shots and make a few birdies out there as well . ' Long-hitting American Dustin Johnson , the world No 9 , carded a 78 that included five bogeys and a double . 'Whether it 's into the wind or down-wind , it was playing very difficult , ' said Johnson . ' I did n't hit it very good , I did n't drive it very well so that made it even tougher . My score is terrible but I 'm still not out of the mix , I guess . ' World No 6 Jordan Spieth and fellow American Zach Johnson , a twice former winner of the Texas Open , were among the day 's late starters .
Graeme McDowell pulled out of the Valero Texas Open after nine holes . McDowell hurt his left ankle in practice and played heavily strapped . He said that 'getting fit is imperative ' coming into The Masters at Augusta . McDowell was five over par when he withdrew in San Antonio on Wednesday .