Born in the Majorcan town of Calvià, Fernández, at just two years old, moved with his family to Caldes de Montbui, where he first came into contact with the world of roller hockey. He played hockey in Caldes at school and in the first-year youth category. He then moved over to the Vic team, where he played for 11 years. After spending three years at the Roncato Patí Vic club, Sergi Fernández joined Barça in the summer of 2010. Since then, he has rubbed shoulders with Aitor Egurrola on the playing field, in addition to attaining a vast number of titles over the years. His cool under a hockey stick has made him into a reliable and regular goalkeeper. His greatest test was being substitute for Víctor Agramunt as goalkeeper for the Vic club. He is one of the greatest goalkeepers in the world thanks to his superb reflexes and ability to react, as well as being one of the few goalies to deflect so many balls with his helmet.