Manuel Preciado has died at the age of 54 just one day after agreeing to become Villarreal's new manager.
The shock death was confirmed by Preciado's former club Sporting Gijon, who were relegated from La Liga this season.
It is understood that the Spanish coach was due to be unveiled to the media as Villarreal's new boss at a press conference tomorrow.
Preciado's recent managerial stint was at Gijon, where he took charge of the club for six years.