Roberto Mancini has warned his Manchester City players that, if they refuse to take responsibility and "never think it's their fault", they will not be part of the team. City travel to Aston Villa with hopes of retaining the title receding. Although Mancini was pleased with his side's 2-0 defeat of Chelsea in their previous game, he was clear his squad should always accept responsibility for their performance.

"I'm not rude with my players," he said. "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. 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% always."

Mancini is rare among managers in being comfortable offering public criticism. But is this wise given the sensitivity of footballers? "I am sensitive sometimes. When they don't play well I'm sensitive," he said. "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 thenext game.'

"I don't like players that never think it's their fault. These players can't play with me. 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."

Mancini believes he learns more from players in defeat. "When you win, like last year [the title], it's easy," he said. "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 has criticised Samir Nasri and Joe Hart and discussed in general terms some of his squad who "think it's enough to play 50%". Asked if Nasri has a long-term future at the club following a disappointing season, Mancini said: "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 [Hart]. 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."

Does Nasri have any issue with Mancini's criticism? "No. Samir knows. I spoke with Samir many times about this. He worked well [this week]. I don't think he wants not to play well but it's my opinion that, if you are a player with the quality that Samir has, you should play well and be important in every game.

"Samir is one of the best players in England. He showed this with Arsenal, he showed this with us last year and also this year sometimes. Against Newcastle before his injury he played incredibly well. It's other players as well. If we didn't score the same goals last year, it's because we missed chances."

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