Roddick withdraws from world finals

LONDON -- Andy Roddick is withdrawing from the season-ending ATP World Tour Finals because of a left knee injury.

The No. 6-ranked Roddick hurt his knee at last month's Shanghai Masters.

The ATP said Tuesday that French Open runner-up Robin Soderling, No. 9 in the rankings, will take Roddick's spot in the eight-man field.

The draw for the tournament is Wednesday, and play starts Sunday. The other participants: Roger Federer, Rafael Nadal, Novak Djokovic, Andy Murray, Juan Martin del Potro, Nikolay Davydenko and Fernando Verdasco.