Villarreal captain Raul Albiol agreed to the terms of the contract extension for next season.
The Yellow Submarine are planning team changes before the new season with a major sale expected to finance reinforcements.
However, alongside new signings, the club is also making decisions on a host of players with expiring contracts.
Former Liverpool defender Alberto Moreno has already left, after five seasons in Castellon, with the 32-year-old planning to stay The league next season.
Despite their willingness to let Moreno leave, Albiol's experience is seen as vital, with the 38-year-old making 24 league starts last season.
The two sides have now agreed to extend their tie for a further 12 months, in what would be their 21st season of top-flight football across stints in Spain and Italy, according to the latest from Relief.
He will become the oldest outfield player in the League next season with a five-day lead over Real Madrid captain Luka Modric.
