Adrian Lopez is reportedly in Villarreal undergoing a medical with the Yellow Submarine.
Earlier this month, Porto boss Julen Lopetegui revealed that the 27-year-old was free to seek pastures new this summer.
A host of clubs have been linked with a move for the former Atletico Madrid attacker, but according to Cadena SER, Adrian is currently undergoing a medical at Villarreal.
The forward's contract at Porto still has four years left to run, but injury restricted him to just nine league appearances last term.
Villarreal have already brought in the likes of Cedric Bakambu, Roberto Soldado and Leo Baptistao to boost their forward line this summer.