Watford chose to sack Javi Gracia last week after a board meeting.
The Daily Mail says Gracia's sacking was virtually assured on Thursday when talks between leading members of the club's hierarchy was called to take place on Saturday morning with a view to calling time on the 49-year-old's tenure at Vicarage Road.
But internal confirmation of Gracia's exit and Quique Sanchez Flores' arrival is believed to have been taken on Friday evening, meaning the meeting was ultimately cancelled.
Nevertheless, while Watford staff were well aware that Gracia's job was in serious jeopardy - news of the managerial changes still came as a shock on Saturday afternoon.