The Daily Mail says City delayed sacking Mark Hughes by three weeks in order to give new manager Mancini an easy start to his Eastlands career.
City fired Hughes after Saturday's 4-3 home win over Sunderland even though the team are sixth in the Barclays Premier League and have lost just two games.
Last night it emerged a verbal agreement on Mancini's three-and-a-half-year contract was reached on December 2, as City beat Arsenal in the Carling Cup, but the board wanted to delay the appointment until after tough games against Chelsea, Bolton and Tottenham.
Mancini, set to earn £10million during his time at City, will begin his reign with fixtures against Stoke, Wolves and then Middlesbrough in the FA Cup.
The 45-year-old Italian is a friend of City chairman Khaldoon Al Mubarak and will be presented at a press conference today.