Lleyton Hewitt announced his withdrawal
from the Tennis Masters Cup yesterday due to the impending birth of his firstborn with wife Bec Cartwright, and this paved the way for Gaston Gaudio to enter the field as well. With Andy Roddick's withdrawal (made official just an hour ago), David Nalbandian enters the eight-man field and Mariano Puerta becomes the alternate.
From the Tennis Masters Cup
"Though I have tried to continue with practice, the lower back spasms