Valencia have sacked head coach Javi Gracia after 10 months in charge.
The La Liga side's 3-2 defeat by Barcelona on Sunday saw them drop to within six points of the relegation zone.
The former Watford boss leaves having won just eight games this season.
A statement said: "The club wants to publicly thank [Gracia] for his work and dedication during these months leading the team and wishes him the best of success for the future."
The six-time Spanish champions are currently 14th in the table with four fixtures left to play.
Assistant manager Salvador Gonzalez 'Voro' will lead the first team on a provisional basis.