Deal is done as Hernandez signs for Leeds United
The Spain international has signed an initial six month deal, but the club has an option to extend this by 12 months at the end of the agreement.
Hernandez, 31, has been on loan at Elland Road since August, making his debut in the EFL Cup penalty shoot-out victory over Fleetwood Town and going on to prove a popular member of the first team with some impressive displays in a number 10 role.
He has made 18 appearances, scoring three goals, since arriving from Al-Arabi. He previously played for Valencia, Getafe and Swansea City, where he met Leeds head coach Garry Monk.