UEFA is requiring some changes to be made in El Madrigal as Villarreal prepares for another season in Europe, and a number of season ticket holders are going to be upset.
According to submarinoamarillo.net, the press area will be expanded and some entrances and hallways enlarged. This can probably be done without too much trouble, but apparently UEFA is also requiring there be more room at either end of the pitch (in fairness, there is not a lot) so two rows of seats will have to be removed at each end behind the goals.
One is also going to be removed at the front of the tribuna, which will inconvenience some very loyal subscribers. Exactly how the club will reassign seats to those affected isn't clear, but typically they have worked very hard to keep their subscribers happy and I would expect the club will do the same this time.