The official, speaking of the sidelines of a ceremony after the pope elevated new cardinals, said the status of the meeting was still pending.
"It will depend on his health," the prelate said.
At present, the pope is only scheduled to meet Fidel Castro's younger brother, President Raul Castro, 80, whose formal title is president of the Council of State and president of the Council of Ministers.
Raul Castro is due to welcome the pope at Santiago de Cuba on March 26, hold private talks with him in Havana on March 27, and see the pontiff off when he leaves Havana for Rome on March 28.
There is no mention of Fidel Castro on the official program.