The Sun says the Italian coach's fate was virtually sealed at a board meeting held by the club's hierarchy just hours before Saturday's limp defeat by Wigan.
And it seems Mancini's swipe at City chiefs after the game looks to have been the final straw.
Now the axe is set to fall before the club depart on a post-season trip to New York next Monday, with Malaga's Chilean coach Manuel Pellegrini lined up as successor.
Before then the out-going champions have two more league fixtures to fulfil - against Reading tomorrow night and then at home to Norwich next Sunday.
Mancini could yet be in charge for those as compensation for the four-year deal he agreed last summer after their title triumph has yet to be finalised.