Fernández made his first-team – and La Liga – debut on 24 August 2014, starting in a 3–1 home win against Getafe CF.[2] The following day, he extended his contract until 2019.[3]
On 20 July 2017, Fernández was loaned to Segunda División side CF Reus Deportiu for one year.[4] He scored his only goal as a professional on 22 October, being essential as the visitors beat UD Almería 1–0.[5]
On 7 August 2018, Fernández terminated his contract with Celta.[6] In the following years, he played abroad with Miedź Legnica (Poland)[7] and Asteras Tripolis FC (Greece).[8]