The Bramall Lane boss went into the new season still struggling to convince a significant majority of Blades fans of his quality and a midweek League Cup defeat at Hartlepool followed by a 3-0 home reverse against QPR looks to have sealed his fate.
Ironically the final nail in Blackwell's coffin looks to have been hammered in by former United supremo Neil Warnock and his new side.
The Blades, together with their new manager will travel to the City Ground on 28 September to face Nottingham Forest in the Championship.