Gael García Bernal agreed to reprise his role as young Che Guevara having previously portrayed him in the television film Fidel (2002 film). To prepare for the role, he went through six months of intense preparation. This groundwork included reading "every biography" about Guevara, traveling to Cuba to speak with Guevara's family, and consulting with Guevara's then still living travel partner Alberto Granado. Despite being in his eighties, Granado was also taken on as an adviser by Salles, and enthusiastically followed the film crew as they retraced his former journey.