As soon as Home Depot Center was enveloped in silence, a pregame tribute to Clive Charles, Shannon MacMillan knew watching from the bench wouldn't be enough.

The veteran forward, who played for Charles at the University of Portland and considered him a father figure, on Monday night made her first appearance in a match since suffering a torn anterior cruciate ligament in May, getting in 20 minutes in the U.S. women's national team's 5-0 destruction of Costa Rica in a World Cup preparation before 12,349.

Shannon Boxx scored in her U.S. debut and Kylie Bivens, the other surprise selection to the 20-woman U.S. roster had a strong 90 minutes at right back as the Americans dominated every phase of the match.

Aly Wagner scored a beautiful goal to fire the Yanks ahead in the 17th minute and crossed for Abby Wambach's header to make it 2-0 in the 41st. Boxx and Cindy Parlow scored four minutes apart early in the second half, and Mia Hamm added the fifth in the final minutes.

There could have been far more, but myriad U.S. shots barely cleared the crossbar or went wide of the frame. Costa Rica goalkeeper MaryClare Herra made one sensational save, diving to poke aside a sharp Wambach header in the 61st minute. Angela Hucles hit the left post in the 14th minute, and Cindy Parlow cracked a shot off the crossbar in 62nd.

U.S. goalkeeper Siri Mullinix touched the ball just twice, once while taking a goal kick, and the Americans outshot their guests, 32-0. The Costa Ricans bunkered in with nine defenders around their box and only a rare occasion held possession beyond the midfield stripe.

MacMillan, whose return to the U.S. squad was called ''miraculous'' by Coach April Heinrichs, was bawling during the moment of silence for Charles, who died last week after a three-year battle with prostate cancer. Heinrichs had left it up to the forward whether she would see any action, and the tribute to Charles cemented her decision.

''I was tossing [the idea of playing] around all day, talking to a lot of people,'' MacMillan said, ''and I've got to be honest: When I heard the moment of silence for Clive, I knew I had to get in there. So when [Heinrichs] turned around in the 69th minute, I just gave her the thumbs up.''

MacMillan, who tore her right ACL while playing for the WUSA's San Diego Spirit on May 18 and underwent surgery two days late, came on for Wambach in the 70th minute, got several touches on the ball and pronounced herself pleased with the effort.

''I felt good. I definitely hesitate a few times, but April told me, 'Just go out and do your thing. If you need to pull out, pull out. Be careful, be smart.'

''But it felt good. It felt good to get that hurdle out of the way, and now I can focus on [taking the next steps].''

Vanessa Rojas, a senior-to-be at nearby North Torrance High School, made her debut for Costa Rica, coming on in the second half.

Rojas, who plays for Fram, one of Southern California's top clubs, contacted Coach Ricardo Rodriguez by email, sent him a videotape of her in action and was invited to join the team when it arrived in Southern California.

MONDAY'S SUMMARY

Sept. 1 at Carson, Calif.

United States 5 Costa Rica 0. Goals: Wagner 17, Wambach 46, Boxx 53, Parlow 57, Hamm 82.

United States — Mullinix; Bivens, Sobrero (Fawcett, 46), Reddick (Chastain, 46), Slaton (Pearce, 46); Boxx; Roberts (Foudy, 46), Wagner (Hamm, 46), Hucles (Lilly, 46); Parlow, Wambach (MacMillan, 70).

Costa Rica — Herra; Aguilar (V. Rojas, 81), Segura, Trujillo, Salazar, E. Rojas (Campos, 37); Megan Chavez, Briceno (Acosta, 86), Solano (M. Rojas, 76), Rodriguez (Wilson, 87); Castro (Martha Chavez, 61).

Yellow cards — Costa Rica: Segura 49, Aguilar 66.

Referee — Sandra Hunt.

A — 12,349