[4] On 2 September 2012, he made his professional debut in the Segunda División, playing the full 90 minutes in a 0–0 away draw against Racing de Santander.

[9] On 21 June 2016, Hernández signed for Premier League champions Leicester City in a free transfer on a four-year deal.

[10] He made his competitive debut on 7 August, coming on as a 63rd-minute substitute for Danny Simpson in a 2–1 loss against Manchester United in the FA Community Shield.

[14] On 24 January 2017, after spending just six months in England, Hernández returned to Spain and its top level to join Málaga on a three-and-a-half-year deal for an undisclosed fee.

[17] Hernández scored his second goal for the team on 12 June 2019, in a 4–2 defeat to Deportivo de La Coruña in the first leg of the promotion play-offs semi-final.

[22] His team came runners-up in the Israeli Premier League in his first season,[23][24] and he also scored in extra time to help them defeat Hapoel Tel Aviv 2–1 in the final of the State Cup.