Hernández scored his first goal for Valencia on 27 November 2008, in a 4–0 win over Rosenborg in the group stage of the UEFA Cup, after an individual effort. After having subbed in for Rubén Baraja in the second half of a home fixture with Recreativo, he netted his second and first in the league, in a 1–1 draw in March 2009. The following month, also as a replacement but now for Joaquín, he added his third, in a 3–1 home defeat of Sevilla – deep into injury time, against ten men.