World number six Andy Roddick dealt the Tennis Masters Cup another blow when he pulled out of the elite season finale with an ankle injury on Wednesday. Roddick, who had been due to face defending champion Roger Federer just a few hours later, said he rolled his right ankle in training and would be out for about a week. The American joins top-ranked Rafael Nadal on the sidelines of the 4.45 million dollar tournament while Federer and Juan Martin del Potro are also carrying injuries.