Andy Roddick loses at World Cup

Updated: May 20, 2012, 5:07 PM ET
Associated Press

[+] EnlargeAndy Roddick
AP Photo/dapd/Patrick SinkelAmerican Andy Roddick returns a ball to Argentina's Carlos Berlocq during their singles match at the Team World Cup in Duesseldorf, Germany on Sunday.

DUESSELDORF, Germany -- Andy Roddick and Ryan Harrison lost singles matches Sunday, giving Argentina an unassailable 2-0 lead over the United States on the opening day of the Team World Cup.

The eight-nation tournament on clay is a warm-up for the French Open, which starts in one week.

Roddick, playing his first tournament since March, lost to Carlos Berlocq 6-2, 6-2 in the Red Group. Leonardo Mayer followed by outlasting Harrison 6-4, 5-7, 6-3.

In the Blue Group, defending champion Germany leads Russia 1-0 after Philipp Kohlschreiber defeated Alex Bogomolov Jr. 6-0, 6-2. Serbia took a 1-0 lead over Croatia, with Viktor Troicki beating Ivan Dodig 6-3, 7-6 (3).

Also in the Red Group, Tatsuma Ito put Japan up 1-0 against the Czech Republic by stopping Radek Stepanek 3-6, 6-4, 6-4.

Copyright 2012 by The Associated Press