Mezue ahịrịokwu na-esonụ: A mụrụ Fernández na Santa Clara, Cuba. O mere mgbalị atọ na-agaghị aga nke ọma iji gbaga United States tupu ya emechaa nwee ihe ịga nke ọma na 2008. O debanyere aha na Braulio Alonso High School na Tampa, Florida, ndị Marlins họpụtara ya na agba nke mbụ nke MLB draft 2011. Fernández mere mbido MLB ya na Marlins na Eprel 7, 2013. A kpọrọ ya aha ndị
2013 National League All-Star Team, ma merie National League (NL) Rookie nke ọnwa Award na July na August. Mgbe oge ahụ gasịrị, ọ meriri NL Rookie nke Afọ Award wee bụrụ onye nke atọ na ntuli aka Cy Young Award. A wara ya ahụ Tommy John n'oge oge 2014 ma kpọọ ya na egwuregwu All-Star nke abụọ ya na 2016.