Platt took last week's conference, saying his manager had other things to do, but Mancini was his usual charming self this week, laughing as he took the mask off, a gesture that diffused some of the tension that had grown between Mancini and the media recently.
Speaking at the club's training ground at Carrington, near Manchester, he said City had no interest in buying Luis Suarez from Liverpool, that Mario Balotelli was not in the squad against Tottenham Hotspur last week because he did not train hard enough but was not being sold, and that his own future at the club was not in doubt.
Mancini, clearly tired of speculation that he is leaving the club he piloted to their first title for 44 years last season, said: "It is not true, I do not know where you get this from.
"For two weeks we talk about Monaco, after [Pep] Guardiola, after another manager, now Suarez, now Mario.
"We have a good team and we don't need to buy another player in January.
"We can't buy Suarez or any another player because we have four strikers. Suarez is a top player but he plays for Liverpool."
Mancini also dismissed rumours linking Balotelli with a move back to Italy.
"No, he is not [going]. He did not play last week, but that was my choice. I have 20 players and if there are some players who don't work well, they don't deserve to play and Mario is just like any other player.
"There were other players who were working better than Mario and they deserved to be on the bench or play. He is an important player for us, and we are not thinking of selling him in January."
City are the only unbeaten team in the Premier League and should preserve that record when they face erratic Aston Villa at home on Saturday.
Even though they have not played particularly well this season, they are second in the table, two points behind leaders Manchester United, and showed their resilience last week when they came from behind to beat Spurs 2-1 at the Etihad.
