Fidel Castro, who once dreamed of playing for the Washington Senators, attended last night's game between the Cuban National Team and the U.S. Pan American baseball team before 30,000 in Havana.

Before the game, he spoke to the Cuban team from his seat behind the plate, then went to the visitors dugout to greet U.S. Coach Ron Fraser and shake hands with each of the U.S. players . . .

Bob Horner, whom fans picked for the Japanese all-star game, might not be able to play because of a sprained back. He got 167,062 votes as a first baseman, the second-most popular vote-getter overall. Managers chose the nonstarters, including Randy Bass, Dick Davis and Tony Brewer . . .

The Korean College All-Stars, 20 of the best amateur players in Korea, will be in the Washington area for three games against local teams in preparation for their annual series with the U.S. College All-Stars. They will play against Wagner of the Maryland State Baseball Association and Fairfax Furniture of the Industrial League Sunday and take on the Industrial League all-stars Monday before heading to Durham, N.C., for the best-of-five all-star series. Sunday's doubleheader will be at the University of Maryland at noon. Monday's game will be at Olney Manor Regional Park at 7:30 p.m.