MEXICO CITY — In another step toward lifting restrictions on its citizens abroad, Cuba announced Friday that its athletes could sign contracts with foreign professional sports leagues, raising the prospect of a flood of new talent around the world but possibly not much in the United States.

Cuba, a sports-crazed island, has long sought to keep its athletes at home in quasi-amateur leagues, usually prohibiting them from cashing in on multimillion-dollar contracts abroad. Defections, as a result, are common, and this season in the United States the Cuban rookie Yasiel Puig, who defected last year and now plays for the Los Angeles Dodgers, has been one of the latest sensations.

The rule change follows a general loosening of immigration restrictions, even allowing Cubans critical of the government to travel overseas, and a range of steps toward reviving a flagging, state-based economy by allowing Cubans to earn cash on their own.

But a number of caveats would probably limit a surge of Cuban players to the United States.

For one, players signing big contracts will still be unable to repatriate the money because of a cold-war-era American law prohibiting trade with Cuba. In most cases, the limits amount to a few thousand dollars a year.