Villarreal are tracking Watford defender Kiko Femenia ahead of potential swoop next week.
The Yellow Submarine are targeting full back options ahead of the 2022/23 season with Serge Aurier already departing on a free transfer.
The experienced Spanish defender, who can play across the back line, has spent five years at Vicarage Road, following his 2017 move from Alaves.
Reports from the The Athletic claim a deal could be wrapped up for around £3m, following the Hornets relegation, with Mario Gaspar potentially heading in the opposite direction.
Aurier was one of five first team players released by the club as they work on a renewed deal to bring Tottenham midfielder Giovani Lo Celso back to the Estadio de la Ceramica next month.