And now Mancini, a devout Catholic who went to church in Manchester the morning before the dramatic title-triumph, has revealed his belief that his faith ultimately swung things in City's favour.
Mancini reckons his pilgrimage to a holy shrine in Bosnia-Herzegovina during the run-in, proved the key to City overhauling United as the title race entered the home straight.
The City boss travelled to Medjugorje with his wife Federica and daughter Camilla in March, just as his team were faltering and United looked to be on their way to a 20th league crown.
Mancini and his family went to the home of Medjugorje resident Vicka Ivankovic-Mijatovic, who is one of six people in the town who claims to have been visited by the Virgin Mary back in 1981.
"I was in a room with some people, and the visionary Vicka was with me," recalled Mancini to the Mirror.
"At a certain point she smiled at me, looking straight into my eyes, so that I tried to see if she was looking at someone else.
"But, suddenly, she moved towards me so that, at that point, I had no doubts anymore.
"She came towards me, she got near, once again she was looking straight into my eyes. Then she kissed me on my forehead.
"I explicitly felt the sensation of a physical contact with someone I had never met in my life before."