Rose led the Masters after round one but eventually tied for 36th

Justin Rose withdrew from the Verizon Heritage tournament with back trouble, after struggling to a first-round 76 in South Carolina.

Rose, who had four bogeys in six holes on Thursday, decided not to risk further aggravating the problem.

Englishmen Nick Dougherty and Brian Davis both shot 67 to share second at four under after the first round.

Americans Justin Leonard, Davis Love and Lucas Glover are tied for the lead, one shot ahead of a group of 10.

Rose, 27, jointly led last week's Masters after the first round last week before falling back to 36th place.

He was forced into two lay-offs around this time last year because of back pains and took a long winter break to work on his fitness.

He is due back in action at the Wachovia Championship in two weeks' time.

Dougherty, 33rd at the Masters, posted two birdies on each nine while Davis, who did not play at Augusta, carded four birdies in five holes.

Davis raced up the leaderboard with four birdies in his first five holes and he picked up another shot at the ninth to turn in 31.

The back nine was less spectacular with a run of pars broken only by a bogey five at the 12th.

Dougherty was soon under par after a four at the 502-yard second and it appeared his round was about to spark into life with birdies at nine and 10.

However, he did not pick up another stroke until the 395-yard 16th but still finished with a creditable error-free 67.