ESPN: The Italian is extremely unlikely to take the deposed Premier League champions on their post-season tour of the United States - which begins with a game against Chelsea in St Louis on May 23 - and might not even be in charge for their remaining two matches of the domestic campaign.
Malaga manager Manuel Pellegrini is being lined up to replace Mancini, who has been in charge since December 2009.
The Chilean denied he had signed a deal at the Etihad Stadium, but it is understood that he is the probable successor.
Chairman Khaldoon Al Mubarak, owner Sheikh Mansour, chief executive Ferran Soriano and director of football Txiki Begiristain have all failed to back him publicly, and Mancini revealed a fortnight ago that he had received no assurances from the club's owners that he will be there next season.
If Mancini does go before Tuesday's game at Reading or Sunday's home match against Norwich, assistant manager Brian Kidd would be the likely caretaker manager. Mancini's other assistant, David Platt, could be sacked with him.