CARSON, Calif. — Forward Brian Ching and defender Carlos Bocanegra were added today to the U.S. roster that will train ahead of the Americans' opening World Cup qualifier against Barbados this weekend.

Ching, a Kamehameha Schools alum from Hale'iwa, was last on the roster for the 2-0 loss at England on May 28. He plays professionally for the Houston Dynamo.

Bocanegra, often the U.S. captain, missed last weekend's 0-0 tie against Argentina because of a family commitment.

Thirteen of the 21 players on the preliminary roster have previous experience in qualifying. Frankie Hejduk, a 33-year-old defender, has appeared in World Cup qualifiers for the 1998, 2002 and 2006 tournaments.

Five players — Freddy Adu, Michael Bradley, Dominic Cervi, Maurice Edu and Sacha Kljestan — are age-eligible to play at this summer's Olympics, which is an under-23 tournament in which each team also can add three wild-card players over the limit.

U.S. coach Bob Bradley must trim the roster to 18 for Sunday's match and the return leg at Barbados on June 22. The United States had a first-round bye in soccer's North and Central American and Caribbean region, while Barbados defeated Dominica 2-1 in a home-and-home series.

The U.S.-Barbados winner advances to a semifinal group that likely will include Cuba, Guatemala, and Trinidad and Tobago. The semifinals will be played from mid-August to mid-November, and the top two teams in the group advance to next year's regional finals. Three teams from the CONCACAF region qualify for the 2010 World Cup in South Africa, and the No. 4 team meets the fifth-place team from South America in a playoff for another berth.

The only previous meetings between the U.S. and Barbados were in the semifinals of qualifying for the 2002 World Cup. The United States won 7-0 in August 2000 at Foxborough, Mass., then was held scoreless until the 63rd minute before winning 4-0 at Barbados that Nov. 15 to advance to the regional finals.

The roster:

Goalkeepers: Dominic Cervi (no club), Brad Guzan (Chivas USA), Tim Howard (Everton, England)

Defenders: Carlos Bocanegra (no club), Dan Califf (Midtjylland, Denmark), Steve Cherundolo (Hannover, Germany, Jay DeMerit (Watford, England), Frankie Hejduk (Columbus), Oguchi Onyewu (Standard Liege, Belgium), Heath Pearce (Hansa Rostock, Germany)

Midfielders: Freddy Adu (Benfica, Portugal), DaMarcus Beasley (Glasgow Rangers, Scotland), Michael Bradley (Heerenveen, Netherlands), Maurice Edu (Toronto), Sacha Kljestan (Chivas USA), Eddie Lewis (Derby, England), Pablo Mastroeni (Colorado)

Forwards: Brian Ching (Houston), Landon Donovan (Los Angeles), Clint Dempsey (Fulham, England), Eddie Johnson (Fulham, England)