[3] Hernán played his first game as a professional on 12 February 2011, starting in a 5–0 away defeat against AD Alcorcón in the Segunda División.

[6] Hernán scored his first goal in the second tier on 2 March 2013, in a 3–3 home draw against FC Barcelona B.

[8] Hernán was an undisputed starter in 2014–15, featuring in 36 matches – play-offs included – and netting three times[9][10][11] as the Amarillos returned to La Liga after a 13-year absence.

[12] On 22 August 2015, Hernán made his debut in the Spanish top flight, in a 1–0 defeat at Atlético Madrid.

[14] On 26 January 2018, Hernán signed with Sporting de Gijón until the end of the second-tier season and three more.