diomedes antonio olivo maldonado (january 22, 1919 – february 15, 1977), nicknamed "guayubin" for his hometown, was a dominican professional baseball player and scout. the left-handed pitcher appeared in 85 major league baseball pitched over all or part of three seasons between and for the pittsburgh pirates and st. louis cardinals. he was the brother of fellow major leaguer chi-chi olivo, and the father of major league pitcher gilberto rondón.