By Ridge Mahoney

The U.S. women's team has played 20 games this year without being beaten, yet none of those games has greater importance than the Gold Cup semifinal against Mexico Wednesday at Home Depot Center (Fox Soccer Channel, 10 pm ET).

By winning, the USA clinches a spot in the 2007 FIFA Women's World Cup next September, regardless of what it does in Sunday's gold-medal game. And while a win over Mexico, which the U.S. beat two months ago, 3-1, in Rochester, is all but a foregone conclusion, U.S. coach Greg Ryan expects his players to come out aggressively and leave nothing to chance.

Two years ago, the teams met in the final game of the 2004 CONCACAF Olympic qualifying tournament, and the Americans fell behind, 2-0, before rallying to win, 3-2.

"There is added pressure because there is one game and you're in," says Ryan, who would prefer group play to be used for World Cup qualifying as is done in most of the world. "Now, if you lose a game, you still have a shot to qualify by winning your next game and then you're playing against Japan. But there is additional pressure with just a one-game situation.

"It's a funny game. We've all seen games where a team dominates but still loses. That's just the way it is sometimes in soccer, much more so than in other sports."

In the other semifinal, Canada plays Jamaica (FSC, 7:30 p.m. ET). The two semi winners automatically qualify, the losers meet in a third-place match Sunday, and the winner of that game advances to a two-game playoff with Japan.

Abby Wambach, playing in her hometown, scored two of the goals in the 2004 win over Mexico. She's been hobbled by a sprained ankle suffered in the Peace Queen Cup earlier this month, and didn't play in the tournament final, which the Americans won by beating Canada, 1-0, on Kristine Lilly's 116th international goal.

"We played our same style, our same system, we just inserted Natasha Kai," says Ryan. "We played very well. Obviously, we're not quite the same team without Abby because she's been so good for us, but I think we'll probably put Tash in there and go after it like we did in the final of the Peace Cup."

Mexico reached the semis by beating Trinidad & Tobago, 3-0, in Miami Sunday. The U.S. has won all 17 meetings with Mexico and can set a team record for longest unbeaten run.

There are three collegians on the U.S. roster: Heather O'Reilly (North Carolina), Stephanie Lopez (Portland) and Danesha Adams (UCLA). They will play in the NCAA quarterfinals this weekend, with Lopez and Adams squaring off when Portland plays at UCLA Friday night. UNC hosts Texas A&M Saturday in Chapel Hill.

Ryan has used 29 players this year. They've compiled a 16-0-4 record and have extended a 30-match unbeaten streak that dates back more than two years. (A penalty-kick loss to Germany March 15 following a 0-0 tie in the Algarve Cup final is officially recorded as a tie.) Ryan has been in charge for 29 of those 30 games, starting with a 1-0 win over France in March 2005 that marked the start of a new era without veterans Julie Foudy, Mia Hamm, Joy Fawcett, and Brandi Chastain. Their resiliency, as well as their record, has impressed him.

"Over the last course of the last year-and-a-half, it's the one question I've had with this team: How will they handle pressure?" says Ryan. "How will they handle playing in a final of the Algarve Tournament against Germany? How will they do in the Peace Cup without Abby? Every time we get a challenge like that, they respond very well."