It's late spring and a Frenchman's heart turns to...baseball?

Joffrey Roussel dons his cherished New York Mets baseball cap, grabs his mitt, and despite the rain heads to the playing field just outside this small, sleepy town situated about 55 miles southwest of Paris in the Loire River Valley. No, Roussel is not the latest, six-figure salaried addition to the 1986 World Series champions. Rather, this 20-year-old Frenchman, an area native and dedicated American baseball fan, volunteers his time coaching and catching for the French Cubs, a team of young amateurs who hit fly balls in a country where soccer reigns supreme and baseball has never quite made the cut.

Indeed, here on opening day of the US season, a poem lamenting the lack of baseball in France makes its annual appearance in the International Herald Tribune. A stanza of ``The Crack of a Bat,'' by Dick Roraback, a former sports editor of the Paris-based daily, reads:

Now, the golfer is buffing his niblick

And the tennis buff's tightening his strings

And the fisherman's flexing his flyrod

Like a thousand and one other springs

Oh, the sports on both sides of the ocean

Have a great deal in common, at that

But the thing that's not HERE

At this time of year

Is the sound of the crack of a bat.

While baseball exists at the amateur level in France - as it does elsewhere in Europe - most observers would rank France low on the list of countries where the game has gained some ground, such as Italy, last year's European champion, or the Netherlands, usually a tough contender. But baseball in France has recently begun to bud, and the swellings look promising.

``Last year in Chartres, there were only 10 regular players,'' says Roussel, whose French Cubs are one of about 120 amateur teams scattered throughout the country. ``And now, even with the rain, there are 25 players.''

``We gain two additional members each practice,'' adds Thomas Crosneur, who pitches for the young club. ``At this moment, there is a baseball boom in France.''

Philippe Denis, a spokesman for the French Baseball and Softball Federation (FFBS), agreed, adding, ``We receive one application per day to create a new club.''

In two years, the FFBS, which regulates baseball in France and acts as the country's only league, has seen the membership in its four amateur divisions double to more than 7,000 players. Denis says he expects that figure to reach 14,000 by the end of this year. Department store windows also reflect the growing interest in the game, displaying shiny hardwood and aluminum bats and other baseball wares, a sight unseen anywhere in France a few years ago. Sporting goods wholesalers and suppliers say the baseball equipment market has expanded from less than $150,000 in sales four years ago to more than $1 million this year.

``Baseball could become the second, third, or fourth biggest sport in Europe, rather than the marginal sport it has been,'' said Regis Duchamps, an equipment distributor. ``The game is growing very, very fast. The market has been doubling every year for the last three years.''

Like the French Cubs, the new clubs are largely composed of youths with no traditional knowledge of baseball. Clubs enter the league at the cadet, junior, or Division Two levels, depending on age and ability.

But not all the players are French or the level of play so low. Robert Irving, an American player-manager for the Division One team of the Baseball Club de France, exemplifies the US connection. While there are regulations limiting the number of foreign players on the field to two, Americans often hold key positions.

Olivier Dubaut, a 17-year veteran of French baseball and president of the Paris University Club (PUC), the largest club in France with more than 300 players and 16 teams in all four divisions, compared the playing level of Irving's team to that of ``a good American junior college team.'' He compared PUC's Division One team, the defending champion, to that of an American university's.

Irving, whose father played baseball in France in the '60s, says the boom potential exists, but is only in its beginning stages.

``When you see the level of play, you can't really say, `It's a boom,''' he says. ``It's only been in the last couple of years that we've been getting more teams that are really competitive.''

The French get an opportunity to show how competitive they are this week as the European Baseball Cup takes place in Paris for the first time. The five-day event features the best teams from the top clubs in Italy, the Netherlands, Belgium, France, and Spain.

The defending champions are the Italians, who have built a reputation as a major contender and have been likened to a Triple-A minor league club in the United States. At the 1986 world championships the Italian national team beat its US counterpart and finished fourth overall behind the Americans, who took third.

The club from the Netherlands is also considered a formidable force in European baseball, so the greatest hope in Paris is to push France ahead of Belgium and Spain, with which it now shares last place.

But FFBS officials are hoping to get more out of the cup than just an improved image. They believe a good showing by the French team and an attendance of 10,000 or more spectators for the championship final will weigh heavily in convincing city officials that Paris needs a bona fide baseball park. Only eight standard-sized ballparks exist in France, as compared to thousands of soccer fields, and none is located in Paris, where space is limited and real estate is costly.

The European Cup itself will take place at the V'elodrome, a 20,000-seat bicycle racing stadium. At a recent game there, Irving pointed to a flat spot from which the pitcher was throwing. ``They'll put up a real pitcher's mound, bring in dugouts, and AstroTurf-over the [banked] bicycle track,'' he said. ``But they'll take it all away when the cup is over.''

French enthusiasts are convinced that baseball can become a popular spectator sport in France, though nobody in the FFBS can remember a national championship game attended by more than 700 people. The French generally turn out in droves for more traditional European sports. But league officials say the earlier games were not advertised and cite the example of basketball as a transplanted American sport that has won a respectable audience in Europe.

Perhaps the biggest factor in the game's potential, though, is its new Olympic status. Baseball was a demonstration sport at Los Angeles in 1984 and will have that status again in Seoul next year, then will become an official sport at the 1992 games in Barcelona.

``In France and in Europe,'' Dubaut said, ``people are interested only in Olympic sports.''

Sensing baseball's increasing global importance, The French government gave the league roughly $1 million in funding this year, a 130 percent increase over last year's subsidy. To cultivate the interest in baseball among French youths, and to establish a solid base for the game in France, the league has regularly been holding five-day baseball workshops in French schools.

``Three or four years from now,'' said Denis, ``there will be baseball practice in every junior high.''

Baseball was introduced to the French at the International Exposition in Paris in 1889, when the Eiffel Tower was also unveiled. American major league teams twice toured France in an attempt to keep the game alive, and the FFBS was founded in 1924. Until now, however, baseball has never caught on in France. Why?

``That's a question I always ask myself,'' said Dubaut. ``There have always been good baseball men in France, but they were never good organizers.''

Irving had a different idea. ``I think it's the fascination with all things American,'' he said, ``and baseball's just a part of that boom. It's a game that intrigues a lot of French people. It's something they've never seen, especially the young people.''

The French Cubs were founded four years ago after three of Crosneur's friends returned from a vacation in the United States.

``They brought back a bat, a glove, and one ball, and we started with that,'' he said. The foursome applied for membership in the league, which sent the youths more equipment, and the mayor of Chartres - a town still known more for its stunning 13th-century Gothic cathedral than its baseball team - apportioned them a soccer field to play on. With their makeshift baseball diamond, the French Cubs gradually began to take shape, attracting curious onlookers such as Roussel.

Several members of the Cubs say they would someday like to make the national team and play for France at the 1992 Barcelona games. The team has plenty of time to prepare. The French Cubs will play their first exhibition game - their first game ever - this season.