Reports have claimed the La Liga club paid just £2m for the striker.
Perez made 19 appearances for West Ham and scored six goals after joining from Arsenal last summer.
Need a VPN? Or seeking to switch? Then support Tribal Football by clicking here to sign up with our official partners NordVPN. Not only will you receive the best VPN experience, but also great discounts by signing up via Tribal Football. Thanks for your support!