Hernandez has recently been linked with the likes of Genoa and Premier League giants Arsenal.
"The club and the Coach told me that I could leave if the right offer was made and I think that has now arrived," the striker told calciomercato.it.
"They know what I want and they know what they promised me."
"I donít want to lose the chance of playing at the World Cup next summer," added the centre-forward.
"I think playing in Serie A is beautiful, but the desire to be at World Cup 2014 is what has pushed me to ask for a transfer."
Hernandez struggled with knee ligaments problems for most of last season.