Mancini courted headlines last week with some outspoken remarks on the indifferent form of playmaker Samir Nasri throughout what appears a doomed Premier League title defence.
The Italian also picked out goalkeeper Joe Hart for criticism in reaction to some mistakes by the England international.
Some observers have suggested such comments by Mancini - and it is not the first time he has made clear his frustration with certain players - could alienate him from his squad.
But the City boss said: "I'm not rude with my players. I say what I think sometimes and if I think it could be good for my players to understand they could play better, they can do more, I say this because I don't lie.
"I say what I think and sometimes it's important that one player takes his responsibility because when you are a top player you earn a lot of money and you should play at 100 per cent always.
"I am sensitive sometimes. When they don't play well I'm sensitive! This is my opinion.
"When I was a player I always took responsibility. When I didn't play well, I said 'sorry I didn't play well and will do my best in the next game,' and it should be like this.
"I don't like players that never think it's their fault.
"These players can't play with me because this is impossible.
"I want strong players that are upset with me when they don't play but after that show me on the pitch that they deserve to play."
Nasri has not lived up his billing since his £24million move from Arsenal in the summer of 2011, prompting Mancini to suggest he has only played at 50 per cent of his capabilities.
But Mancini insists he has no doubt about what the player can attain and was voicing frustration with the situation.
The Italian said: "I said that, for me, Samir is a top player and a top player should play well in every game.
"I said this and it's the same for Joe. If I am a top player, I want to play well in every game and Samir knows this because I have spoken about this situation with him.
"I think that he can do better because he has quality, technique and he's strong. He can do better, only this."
City's hopes of retaining their league crown seem slim having fallen 15 points behind Manchester United at the top of the table.
They can cut the deficit back to 12 with victory at struggling Aston Villa tomorrow night but the odds on title success would remain considerable.
City have gradually fallen back since losing their last derby clash with United in December but Mancini admits he has learnt more about his players this term.
When asked about this he said: "Yes. When you win, like last year, it's easy. When you have a problem, you should resolve that problem.
"I love all of my players and I can do everything for my players but I want them to do everything for the club."
Mancini believes last year's remarkable triumph may have had a draining effect on his players while the manager has previously admitted not securing the summer transfer targets he wanted.
City began the campaign with high hopes but have not built on what they achieved in 2012, when they overturned an eight-point deficit with six games remaining to finish top.
Mancini said: "I said that sometimes it can happen for a team like Manchester City that didn't win for 30 years, the year after they win a championship it can happen.
"Sometimes we didn't play with the same attitude that we had last year sometimes in some games. It could be normal.
"For this reason we've said that it was important to put another two or three top players in the team because it's important after you win to add more top players because other players that won the championship here before, they should work harder."
City captain Vincent Kompany is unlikely to return to action at Villa Park after calf problems but midfielder Gareth Barry is fit to face his former club after an ankle injury.
It's not about saying what you think, being sensitive or taking responsibility. It's just really bad form to criticise your players to the press. It's not just about what alienates people and what is considered 'right' either. We all know how well-paid footballers are at this level, but as an employee you have a right to expect discussions about your performance to be carried out in private. I can think of nothing more likely to cause unrest than criticising certain players to the press (rather than the team as a whole), and it seems wholly unprofessional to me (regardless of who does it).- big dave