Born in Caracas, Hernández played Spanish lower league and amateur football until the age of 25, competing mainly in the Community of Madrid.

[3][4] Additionally, he represented SD Huesca in the Segunda División in the first part of the 2009–10 campaign, but his input consisted of two domestic cup appearances.

[6] He spent the vast majority of his first year as understudy to Jaime but, due to injury to his teammate, excelled in the promotion playoffs as the team returned to La Liga after a two-year absence, conceding only once in four appearances and three starts.

[7][8] Hernández continued to be first choice in the 2012–13 season, helping the Castile and León side retain their league status after ranking in 14th position.

[9] After a one-year loan in the Super League Greece with Asteras Tripolis FC,[10] he acted as backup to Javi Varas.