Mancini's future at City has been the subject of constant speculation and Saturday's disappointing defeat against Everton has fuelled rumours over his position at the Etihad Stadium.
City saw their title hopes all but ended by the defeat at Goodison Park, but Platt is adamant Mancini will not be affected by the rumours over his future and has offered a staunch defence of the Italian.
"There is an appreciation of Roberto from the supporters and the owners," said Platt.
"The expectancy levels of Roberto Mancini are a lot higher than what people think. If people want to talk about rumours and negatives that is up to them. We can't stop that.
"If people want to do things like that, they can. All I know is that during his career he has won things.
"That is what his focus, desire and intensity is about.
"He won't want stop wanting to win things. He will regroup from this and by the time we play Newcastle he will have 100% focus."