Hernández began racing motocross at the age of 15 . In 2003 and 2005 he won the national championships. In 2008 he made his debut in road racing. In 2009 he finished the season in the Spanish championship of the Supersport class in fourth place overall. In 2010 he made the leap into Moto2 . In the course of the season he collected 32 world championship points in the Blusens STX team and thus secured 19th place in the overall standings. In 2011 he stayed with his team and got 43 points on an FTR machine. Due to an injury to his hand, he had to pause three races. In 2012 , Hernández rose to MotoGP . He scored 28 points for the Avintia Blusens team . The season ended prematurely for him due to an injury.