Sinclair joined City from Swansea last summer for £6.2million, choosing to leave the Welsh side after impressing in the Premier League following their promotion. However, Sinclair managed just 190 minutes of action in the league last season, often completely left out of the club's matchday squad.
Mancini spoke out after the 24-year-old had voiced his displeasure, admitting that he should take the blame for the winger's lack of action. Sinclair has now spoken of his relief at leaving the Etihad Stadium, revealing the strained nature of his relationship with the Italian.
"It's things like that, in the backroom, when he [Mancini] said he didn't give me a chance, which he didn't," Sinclair said.
"I even asked him, 'Why did you bring me in if you're not going to give me a chance? You've given me no game time to show what I'm about', and he couldn't really answer the question.
"As a player, if you're not getting a chance to play, then you are going to see the manager and ask him what is needed. So I did see him a few times, and we had our differences, but that's football. Not being given an opportunity to play was frustrating, but that was the choice I made, I never kicked up a fuss. All I could do was put my head down and train every day.
"I now really hope I can settle here and have a great start from Sunday onwards, score some goals, help to win games and if I'm happy enough then hopefully I'll stay.
"I definitely would think twice about doing it [moving to another big club] at this stage of my career."