The experienced stopper has agreed terms with the newly-promoted Primera Division side, and will be unveiled to the press later on Tuesday upon completion of his medical
The Galician outfit are keen to add some more experience to their squad following their promotion to La Liga, and they have now reached an agreement with the Yellow Submarine over the acquisition of the former Spain international.
The 33-year-old's contract with Villarreal was due to expire in the summer of 2013, but they have opted to let go of the defender for nothing, in light of their recent drop to the Segunda Division.
Marchena will undergo a medical at the Hospital Modelo on Tuesday morning, before being presented to the Spanish media at 19:30UTC.
The 2010 World Cup winner started his professional career with Sevilla, and also wore the jerseys of Benfica and Valencia before joining Villarreal in the summer of 2010.