FLORENCE, JUNE 9 -- The Americans are poised for their first appearance in the World Cup finals in 40 years. The greatest soccer experience of their lives awaits them Sunday at 11 a.m. EDT, when, virtually dismissed here as a threat of any sort, they step onto a world stage to take on highly favored Czechoslovakia. While making no unrealistic predictions, the Americans have made it clear they intend an all-out effort to climb this highest of all hills in Tuscany.

"I'd trade everything else I ever did in soccer to be here," said John Stollmeyer of Annandale, Va., a U.S. midfielder who has been a three-time all-American at Indiana, a regular on the U.S. national team during the 1980s and a member of the 1988 U.S. Olympic team in Seoul.

If Americans in general shared anything close to the emotion the U.S. team brings to this game, the country would come to a standstill Sunday as it does for Super Bowls. But soccer is not America's sport. The United States will not exactly join the global village for what is an historic encounter for the Americans. Word of the outcome, in most cases, will get around in due time.

But this rare appearance by the United States in the soccer stratosphere is expected to increase interest in the sport at least a bit, and soccer could receive even more attention with the United States serving as host to the 1994 World Cup.

The most optimistic American soccer authorities believe the state of the sport at home is much like a blessed infant -- healthy and growing but needing time to reach maturity.

"Soccer has progressed tremendously in the United States over the last couple of decades," U.S. Coach Bob Gansler told reporters from around the world this week. "Initially it was kept alive by ethnic communities. Perhaps we are a little further along than you might think. We have a long way to go. It's going to be an evolutionary process. But we feel we're well on the way."

When the professional North American Soccer League began in 1968, there was talk of a soccer "boom" in the United States. It didn't happen; in fact the NASL went out of business after the 1984 season. But what did happen was a huge growth in youth soccer.

In 1974, 103,000 children registered with the U.S. Soccer Federation. Last year, 1.5 million were registered. Including unregistered players, eight million under the age of 19 play the game in the United States.

The Soccer Industry Council of America estimates that 15.3 million people of all ages are playing soccer. That, according to SICA, put soccer behind only basketball as a participation sport for U.S. youths.

But nothing has brought interest to the levels enjoyed by major professional sports in the United States. "It's a wonderful game that more and more people are finding out about," said Walter Bahr, who played on the 1950 U.S. World Cup team that upset England and is leading the American delegation here. "But there's been no room in our professional calendar for it. So be it.

"But when you've got consistently good players going at each other, then it's just great." That's what happened Friday in Milan when Cameroon went at defending champion Argentina and scored a spectacular 1-0 upset. It would be hard to surpass the electricity of the crowd; it had the breathtaking excitement of a great heavyweight championship fight or the Kentucky Derby. Certainly for excitement it far surpassed most Super Bowls.

But at the moment, soccer in America is stuck in a Catch-22. The best players must go abroad to advance their games and make big money. Tony Meola, the charismatic goaltender and college player of the year last fall, currently is the best example. His agent is shopping for the best deal, soon to be closed, and it will be far from the United States.

These days, young players tend to gravitate to the more popular sports after playing youth soccer. But not all do. Soccer has grown significantly in colleges over the last 15 years -- it is played on at least 780 campuses.

Only two U.S. professional leagues exist -- the American Soccer League and the Western Soccer League. The Washington Diplomats, who play at RFK Stadium; the Washington Stars, who play in Fairfax, Va.; and the Maryland Bays, in Columbia, Md., belong to the ASL. The league's average attendance in 1988, its first year, was about 2,500. Last year it was about 2,600. For business purposes, the two leagues have merged into the American Professional Soccer League, but the only meeting of Eastern and Western teams is in a September championship game.

Without an abundance of world class players and Washington Redskins-type crowds, soccer has struggled to attract much of a television audience. ESPN, the sports cable network, televised the Americans' thrilling 1-0 victory last November over Trinidad and Tobago, the game that got them here. The rating was 0.8 (about 750,000 households). A stock car race shown just before the soccer game attracted a 2.7 rating.

ESPN showed 14 World Cup games in 1986 when the United States wasn't involved and the games got a rating of 0.4.

Yet Americans come out to watch good soccer. In the '84 Olympics in Los Angeles, soccer drew 1.4 million spectators for 32 games, an average of more than 44,000.

The current World Cup is being televised in the United States by Ted Turner's TNT cable network (24 games) and Univisio'n, the Spanish-language network (33 games). Univisio'n, founded in 1961, broadcast to 6 million households and says it had 2.73 million households watch the 1986 World Cup championship from Mexico City between Argentina and West Germany.

After evaluating the rating for this Cup and weighing the possibilities in covering a flavorful world gathering in '94, most if not all of the major networks are expected to bid for the rights. A reported $11.5 million deal struck late last year was overruled because of a question about competitive bidding.

Soccer and television have never made for a happy marriage. TV has not been able to solve satisfactorily the problem of inserting commercials into the game's nonstop action. The possible appeal of the Cup being held in the United States is expected to push the broadcast-rights figure up somewhat.

If ethnic communities have been the heart of the game in the United States -- while abroad, soccer is a passion in working-class areas -- the sport has become popular in the country's suburbs. The networks can't help but notice the interest of people who have money to spend.

Over Memorial Day weekend, four youth soccer tournaments were held in the Washington area: in Columbia, Bethesda-Rockville and two in Northern Virginia. More than 700 teams with players ages 10-19 took part, each team bringing a contingent of relatives and friends who generated revenue for the area.

In the United States, soccer is played predominately by whites. But two black players made this year's World Cup team: Desmond Armstrong, who was born in Washington and after age 7 grew up in the Maryland suburbs, where he came into contact with soccer, and Jimmy Banks, who grew up in Milwaukee's inner city.

Armstrong's family moved from Southeast Washington to Hyattsville, then to Wheaton when he was 11 and to Columbia when he was 14. "Before we moved to Wheaton, I didn't know what soccer was," said Armstrong this week after a practice. "I was playing basketball with a friend whose father was a soccer coach. He asked me to join the team. The first year I was dismal. I couldn't pass from A to B. But things got better."

In another way they got worse. "I was the Oreo cookie," said Armstrong. "You know, black on the outside but white on the inside. I was labeled that by some blacks. But once they got to know me, they knew labeling me was wrong."

By the time he was in Howard High School in Columbia, "I was a respected athlete, not just a soccer player." Following the sport he'd come to love, he went on to the University of Maryland and made the U.S. Olympic team in 1988.

"To some extent," he said, mentioning Banks, "we are role models because we are here. If there's a spot for me, maybe someone else will say, I can do that too.

"In the States you need cable to see the game. You don't see it played. Basketball and football -- that's been the ticket to get out. But maybe there's another avenue. It may be soccer.

"Maybe you're not going to gross as much as in the major sports. But it's a good life. There's travel. Education through travel. For me, playing against Italy in Rome is the major accomplishment in my career."

With the World Cup coming to America, soccer can't help becoming more prominent. Soccer officials see the Cup as the opportunity to increase public interest and support from the business community. But if soccer is to approach status as a major spectator sport it will take time, they say.

For now, just making the World Cup finals is an achievement that culminates several successes in 1989 by U.S. national teams competing in five-a-side, under-20 (age group) and under-16 events. Said Michael Windischmann, captain of the team, "It's a dream to play in the World Cup for all of us."Special correspondent Steven Goff in Washington contributed to this report.