Andy Roddick heads into the fourth round of the Nasdaq-100 Open with only sketchy information about his next opponent. "I know what he looks like," Roddick said. Qualifier Simon Greul is a 24-year-old German ranked 130th. He came to Key Biscayne with a career record of 1-5 on the ATP Tour. Unnerved playing on the stadium court Monday, he won a total of four points in the first set against Tim Henman.