Manolo Preciado has passed away Wednesday night at the age of 54 after suffering a heart attack in his hotel room in Valencia.
The former Sporting Gijon trainer was only just appointed as Villarreal's new head coach on Wednesday, and was due to be presented to the press and public on Friday.
Preciado played for clubs such as Racing Santander, Linares, Mallorca, Alaves, Ourense and Gimnastica during his active career, before becoming a coach at the club where he retired.
The El Astillero-born coach most notably worked for Sporting Gijon, where he was the man in charge from 2006 until 2012, and steered them to the Primera Division in his second year at the club.
Preciado was dismissed as Sporting boss earlier this year, but was set to return to the bench at relegated Villarreal in the 2012-13 campaign.