Serratos is not shy about sharing his dreams. He wants the Capitanes to build an enormous fan base and become a recognized sports brand across Latin America. He wants them to win games and vie for championships. And there is, of course, his biggest dream of all, one shared by the team’s owners: for the Capitanes to become an N.B.A. franchise. “It will, of course, be a big challenge,” he said. “But I like big challenges.”