The New York Yankees, formerly a symbol of sports success in baseball-rich Cuba, might regain some of their lofty stature on the island.

Cuba, once a fertile breeding ground for major league players, has not had any professional sports since Fidel Castro came to power in 1959. Since then, any coverage of professional sports has been banned from the Cuban air waves, with the concentration instead on amateur competitions and Cuban and Soviet-Bloc athletes.

Along comes Radio Marti, the U.S. government's curve ball to the Castro regime. Radio Marti, the White House's controversial initiative to broadcast "the truth" to the Cuban people, went on the air two weeks ago, providing 14 1/2 hours a day of news, features, anti-Castro commentary, soap operas and entertainment, including sportscasts and major league baseball play-by-play.

Like Radio Free Europe and Radio Liberty in Eastern Europe, Radio Marti intends to supplement the controlled news media in Cuba. The station, named for 19th century Cuban liberator Jose Marti, is an arm of the Voice of America and broadcasts at 1180 kilohertz on the AM band from a 50,000 watt transmitter in Marathon, Fla.

The programming originates here, in Spanish, from VOA's studios in Southwest Washington. With no correspondents in Cuba, Radio Marti's task is made harder in trying to gauge the interests and awareness of the Cuban people.

Such is the problem for Guillermo Portuondo, a native of Santiago, Cuba, who does four sportscasts daily for Radio Marti. Portuondo's Cuba, the one Castro shattered with his revolution, now is a generation removed.

"It was my whole life, something money could never replace," said Portuondo, 60, who had worked for the newspaper El Pais for 20 years before Castro took power. "I was devastated, the best years of my life gone . . . I don't want to go back. I want to keep the image of Cuba I know before Castro."

Portuondo, who has worked for VOA since 1961, tries to monitor his homeland's sports pulse through the mail he receives and by talking to friends in the Latin American press at such events as the Pan American Games.

During his seven-minute sportscasts, he concentrates on the Cuban passions for baseball and boxing. He has done interviews with Muhammad Ali, baseball hall of famer Juan Marichal and Cuban-born baseball players Sandy Amoros, Barbaro Garbey and Tony Perez.

Portuondo also gives news of track and field, amateur basketball and soccer. He stays away from football, golf and tennis, professional sports in which Cubans have little interest and knowledge.

He does not expect much feedback from the Cuban community, but he is convinced his sports reports have a positive impact.

"It's very important for the Cubans," he said. "They follow sports, that much we know. It's important, if only because Radio Marti gives them a relief from the everyday Cuban propaganda. You'd be surprised at the mail I was getting (while working for VOA's Latin American division). 'What's Minnie Minoso doing now?' 'How about Stan Musial?' they would write.

"When it comes to professional sports, they get absolutely nothing. Nothing," Portuondo said. "Not too many people there knew Sugar Ray Leonard was a professional until they heard it on VOA. It's difficult to believe, but that's a fact."

Radio Marti hopes to increase its penetration of the Cuban psyche with live broadcasts of major league baseball games. Radio Marti's program director, Richard Araujo, said that broadcasts of Yankees and New York Mets games could begin as soon as next weekend. Radio Marti will handle about 30 games, mostly on weekends.

Araujo is interested in doing play-by-play of some Detroit Tigers games because Garbey, who came to the United States as a refugee on the "Freedom Flotilla" in spring 1980, plays for them. Radio Marti also will try to broadcast playoff and World Series games.

"We will do live boxing when it merits it," Portuondo said. On its first day of operation, Radio Marti provided round-by-round descriptions of the Larry Holmes-Carl Williams heavyweight title fight until the station went off the air for the night shortly after 11.

Other live events Radio Marti might do, according to Araujo, are World Cup soccer games and the Pan American Games.

Portuondo says he will never go home. After he left, his mother and four brothers died there without him ever seeing them again. His sister recently had a stroke, and he would love to see her, but he's resigned to his fate.

"I can't go back," he said. "They say I betrayed Cuba. I do miss it. My sister understands. She knows it would be from the airport to the jail. Not even that. I'd have to get a permit to go there, and I wouldn't ever get that."