Jordan Spieth has failed to make the cut at the Shell Houston Open as South Korea's Sung Kang opened up a six-shot lead at the halfway stage.
Spieth would have hoped to be competing at the top end of the leaderboard ahead of next week's Masters, but his second-round 77 cost him his place at the weekend.
Adam Scott, Patrick Reed, Henrik Stenson and Lee Westwood also under-performed before their trip to Augusta, but there were no such problems for Sung as he posted a 63 on Friday.
He sits six shots ahead of Hudson Swafford and Russell Henley, while Rickie Fowler dropped to fourth position after only registering a score of 71.
England's Justin Rose currently sits just outside of the top 10, but former world number one Luke Donald is down in 40th place.
