Pheonix ? Shouts of “Viva Mexico!” might drown out chants of “U-S-A, U-S-A” when the United States takes the field for its World Baseball Classic opener today.

At least a quarter of Arizona’s five million residents are Hispanic, so there should be a strong show of support for the “visiting” Mexican team among the 30,000 or so expected for the game at Chase Field.

A hint came Saturday, when a festive crowd packed Tucson Electric Park to cheer on Mexico’s 6-1 exhibition victory over the Arizona Diamondbacks.

“I expect them to be very supportive, and I think that will fuel the USA fans once they get into this atmosphere,” U.S. manager Buck Martinez said Monday. “From my understanding in Tucson, they had sombreros and their faces painted and a lot of Mexican flags. It was a bullfight kind of atmosphere, so that will be beautiful in this tournament.”

Team USA will send Jake Peavy of the San Diego Padres to the mound.

“This is probably the coolest thing I’ve ever done on a baseball field,” the 24-year-old right-hander said. “To be with this group of guys, have a chance to represent my country in America’s pastime, I can’t put into words what it means to me.”

Mexico will start Baltimore Orioles right-hander Rodrigo Lopez.

“This Mexican team, they’re not running out slop,” Peavy said. “They’ve got a very good baseball team with a lot of proven major-league players on that roster. Rodrigo Lopez, his credentials speak for themselves. He’s capable of shutting anybody out on any given day. He shut the Yankees out all the time, and that’s basically the same lineup we’ve got.”

The three Yankees on the U.S. roster – shortstop Derek Jeter, third baseman Alex Rodriguez and outfielder Johnny Damon – will be in the starting lineup today. Damon, though, will shift from center field to left, with Ken Griffey Jr. starting in center.

“We’ve faced him 100 times playing with Baltimore,” Jeter said, referring to Lopez. “He’s always been pretty tough. He knows how to pitch. He mixes it up.”

Lopez was 15-12 last season with a 4.90 earned-run average. Despite a series of injuries, Peavy was 13-7 with a 2.88 ERA.

The U.S. players repeatedly have talked about the national pride and team camaraderie they had experienced since they gathered for their first workout Friday.

“The boys just went together and realized what a good time we’re having and hired a photographer to sit there and take candid shots in the clubhouse,” Peavy said. “This is something that you’re going to remember the rest of your life.”

Under rules designed to prevent the overuse of pitchers during what would normally be spring training, starters can throw no more than 65 pitches. Peavy is set to go three innings only, whether he reaches 65 pitches or not. But the emotional young hurler does not plan to hold back.

“I’m going to let it all hang out for three innings,” Peavy said. “What I’ve got to bring to the table, Mexico’s going to get it tomorrow.”

Martinez said his lineup would lead off with Damon, followed by Jeter, Griffey, Rodriguez, designated hitter Mark Teixeira, first baseman Derrek Lee, catcher Brian Schneider, right fielder Randy Winn and second baseman Chase Utley.