The Argentina striker has agreed a four-and-a-half-year deal and could join the Latics in a deal worth up to £7million.
“I found out eight or nine days ago,” Ruben told Villarreal’s official website.
“Since then the club have continued with negotiations with my agent and he told me it was done and all that was needed was my signature.
“I am happy to take this opportunity because it is a good coach (Roberto Martinez) and a great team.”
