Born in Tucumán, Hernández moved to Buenos Aires at early age, and subsequently joined Racing Club's youth setup.[2] He was released in 2005, aged 19, and returned to his hometown. After failing in a trial at San Martín de Tucumán, Hernández moved to Atlético Tucumán. He made his senior debuts in 2006, and moved abroad two years later, joining Racing Montevideo.
On 7 August 2009 Hernández moved to Defensor Sporting.[3] He made his debut on the 23rd, starting in a 5–1 home routing over Atenas de San Carlos, and scored his first goal roughly a month later, netting the last of a 4–0 win at Central Español.
Major League Soccer
On 1 July 2010, D.C. United officially announced the loan signing of Hernández from Uruguayan club Defensor Sporting, after he trialed with the club.[4] Despite being a regular starter for DC United, he rescinded his link on 7 January of the following year,[5] and moved to Argentinos Juniors late in the month.[6]
Hernández appeared with the side in 2014 Copa Libertadores, appearing in all matches as his side were knocked out in the group stages.[9]
Celta de Vigo
On 26 June 2014, Hernández moved teams and countries again, after agreeing to a four-year deal with La Liga side Celta de Vigo,[10] for an € 1.6 million fee.[11] He made his debut for the club on 30 August, replacing Nolito in the 85th minute of a 1–1 away draw against Córdoba CF.[12]
On 4 July 2018, Hernández returned to his natal Argentina and signed with Independiente.[14]
Return to O'Higgins
In July 2021, Hernández returned to Chilean side O'Higgins after ending his contract with Independiente.[15] After two and a half seasons with them, he retired from professional football at the end of the 2023 season.[16]
San Martín de Tucumán
In 2024, he returned to professional football by signing with San Martín de Tucumán in his city of birth.[17][1]
International career
Eligibility
Since Hernández has Chilean Citizenship through Jus sanguinis principles in December 2013, he is eligible to play for Chile. Hernández was born in Argentina and is an Argentine citizen; he thus had the choice of either playing for Chile or Argentina.[18]
When asked about his choice in a 2013 interview, he stated:
I feel Chilean largely. During my first year I lived with my grandmother. I have a great affection despite the short time I've been in Rancagua. It was up the possibility for blood right and thank God, yesterday (Tuesday), I received my documents formalizing and dual nationality.
— Hernández speaking about his switch of allegiance.[19]
In June 2014, Hernández was called up to the provisional 30-men squad for the World Cup in Brazil, however an injury ruled him out of the final squad. He was re-called to play in the friendly match against Bolivia on 14 October 2014, where he was victim of a penalty that Arturo Vidal changed for goal and the final 2–2. In November, he was called to play against Venezuela and Uruguay, Hernandez scored the fifth goal in the 5–0 win against Venezuela in Talcahuano.