( CNN ) -- Some athletes respond to a proverbial kick up the backside , but Rory McIlroy seems to have found inspiration from the prick of a cactus thorn . The Northern Irishman canceled a humanitarian trip to Haiti to play in this week 's Texas Open , hoping to rediscover his form ahead of next week 's Masters . The two-time major winner added San Antonio to his Augusta buildup after registering just one top-10 finish since signing a lucrative deal with Nike in January which could be worth as much as $ 250 million , and losing the top ranking to Tiger Woods . While Thursday 's first-round 72 left him five strokes off the lead , McIlroy roared back with a five-under-par 67 that left him two off the halfway pace . The world No . 2 had a mixed opening few holes , and he dropped his second shot of Friday 's second round following a close encounter with a flower of the desert on the ninth fairway . `` I should n't have been there anyways , so I guess it was deserved , getting a -- whatever it was -- off the cactus , '' McIlroy said on the PGA Tour website . The 23-year-old responded with a birdie at 11 , and three more at the last three holes to end the day tied for fifth and in sight of pacesetter Billy Horschel . `` I definitely feel like I made the right decision to come here , and even if I had n't been in this position and have been a few shots back I 'd still feel the same way , '' McIlroy said . `` I have n't really been in contention this year . So it will be nice to get into the mix . '' While his shotmaking has been erratic at times , McIlroy 's long game is in fine shape . He managed to get to the green in two at the par-five eighth and 18th -- the latter after a 325-yard tee shot -- though he missed eagle putts at both . `` I think that shows where my game is , '' McIlroy said . `` Those two par-fives are probably the toughest to hit in two with how small the greens are . It shows that my ball-striking is there . If I can keep hitting shots like that into par-fives , I 'll be doing OK. '' McIlroy tied for 45th at last week 's Houston Open , where Horschel was joint second behind D.A . Points . The American closed with two birdies to sign for a 68 and take a handy lead over compatriots Daniel Summerhays ( 69 ) and Charley Hoffman ( 67 ) as well as Australia 's Steven Bowditch ( 69 ) . Two-time major winner John Daly missed the halfway cut by one shot after following up his 76 with 70 , finishing birdie-bogey-birdie .
Rory McIlroy 's form improves after an encounter with a green at the Texas Open . The former World No . 1 shoots five - under 67 to be two shots off the lead . He is hoping to improve his form ahead of next week 's event at Augusta . American Billy Casper leads PGA Tour event after finishing with four birdies .