Washington, which maintains a 37-year-old economic embargo on Cuba, this year authorised the Orioles to visit the island and negotiate playing the games with Cuba in an exception to the sanctions.
The Cubans will be seeking to avenge a 3-2 loss to the Orioles on March 28 at Latinoamericano stadium in Havana in the first game of the two-game series.
Cuba's baseball-loving President Fidel Castro has been attending the team's practice sessions behind closed doors at the Latinoamericano stadium,where they are training in secret for the milestone game.
The series brings together a U.S. professional squad and Cuba's top players in a sports exchange unprecedented in four decades of political hostility between Washington and the Communist-ruled Caribbean island.
Cuba, which practices only amateur sports, has lost several top players to the United States through defections in recent years, among them Orlando Hernandez of the New York Yankees, who helped the team win the 1998 World Series over the San Diego Padres.
About 1,000 exiles are expected to participate in a protest against the series, which some observers dubbed "baseball diplomacy" after the "ping-pong diplomacy" that helped thaw U.S.-China relations in the 1970s.
"I cannot believe that this is happening here in America," Cuban-American congressman Bob Menendez, a New Jersey Democrat, said in a statement.
The New Jersey-based United Cuban Organisation will take about 20 busloads of protesters to the stadium - including members of the powerful Miami-based exile group Cuban American National Foundation - where they will rally around a nearby statue of Cuban independence hero Jose Marti.
"We are going to meet all together around the statue of Jose Marti as a vindication of the democracy that has already been destroyed in Cuba by the Communist regime," said Luis Queral, the event's organiser.
"We will have flags and signs," Queral said. "We're not going to be offensive to anyone but Fidel Castro."
Reuters
