Clarke and Howell withdraw from Wachovia

England's David Howell and Ireland's Darren Clarke have withdrawn from the Wachovia Championship ahead of the second round, citing back and hamstring injuries respectively.

Howell, who has been plagued by injury in recent years, had struggled to an opening 74 while Clarke fared even worse with a 76 which included five birdies and a solitary birdie on the 18th.