Wednesday's three-goal hammering at Tottenham convinced owner Sheikh Mansour and chairman Khaldoon al-Mubarak that Mark Hughes could not steer City into the top four, as had been expected following a summer outlay of £120million.
"A return of two wins in 11 Premier League games is clearly not in line with the targets that were agreed and set," said Khaldoon, in a statement.
"Sheikh Mansour and the board felt there was no evidence that the situation would fundamentally change."
City's victory on Saturday sees them move up to sixth in the Premier League, with games in hand over most of the teams above them.
Yet, after delivering his own assessment of the situation at City last May, when he stated sixth place would be an adequate return this term, it seems Khaldoon moved the goalposts once he knew just how much Hughes wanted for a vast rebuilding programme, which included revamping the club's Carrington training complex.
"Prior to the current season beginning, with significant investment in players and infrastructure in place, the consensus between the board and coaching staff was that appropriate agreed targets should be set," said Khaldoon.
"The targets were agreed as a result of the player acquisition strategy of the club being radically accelerated in the summer as a result of very favourable conditions for any buying club.
"It was also based on the fact that the infrastructure of the club had been overhauled completely at great cost in order to create the best possible environment for the team."
In Mancini, he is bringing in a 45-year-old who guided Inter Milan to three successive Serie A titles from 2006 before being sacked in 2008 after failing to make any impact in Europe.
By installing Kidd as his number two, Mancini ensures he has the knowledge of the English game he currently lacks alongside him in the dugout.
"Roberto is a hugely experienced manager with a proven track record of winning trophies and championships," said Khaldoon. "His experience and track record speak for themselves.
"What is absolutely clear is that Roberto believes in Manchester City's potential to achieve at the highest level and importantly in his own ability to make this happen.
"My hope is that our incredible fans will join us in welcoming Roberto to the football club."