Manchester City manager Roberto Mancini says if he is sacked every other Premier League manager deserves same fate

Roberto Mancini has argued that if he is sacked then every other Premier League manager deserves to lose his job as well.

There has been growing speculation that should Manchester City lose to Leeds in the FA Cup at the Etihad Stadium tomorrow then the club's owners will remove the man who last May led them to their first championship since 1968.

The former City defender, Danny Mills, described the club, which has fallen a dozen points behind United, as "ready to explode". He said: "I think Mancini will go in the summer if they don't win the league but, if they go out of the FA Cup at this stage, I could see the owners making a decision sooner than that.

"There is a rumbling undercurrent of discontent at City," Mills added. "From the outside, it all looks pretty and serene but underneath there is a bubbling inferno ready to explode."

With his voice heavy with sarcasm, Mancini retorted: "Who are these people [demanding he should go]? They are probably the same players who won so many trophies in their history.

"We started our project three years ago. In those three years we have always been on or near the top, we have fought for the title, we have won three trophies and we have the chance to win more this year.

"All the people who talk about this don't understand football because, if they sack me, the other 19 teams in the Premier League should be without a manager."

The City manager, who counts the Community Shield as a trophy in a way that United's Sir Alex Ferguson does not, argues that men like Mills, whom was released by City when his contract expired in 2009, do not understand the mentality of the club's owners.

Sheikh Mansour and City's chairman, Khaldoon al-Mubarak, are not to be compared with Chelsea's oligarch, Roman Abramovich, when it comes to hiring and firing managers.

"We won the Premier League maybe too quickly," Mancini said. "Usually, it would take four or five years for a team like City to do this. I speak to Khaldoon every week. He is like me. When we lose, he has my mentality; he is upset and disappointed but this is normal in football if you have blood inside you.

"After you have lost you cannot be happy for 24 hours; after that you need to think about the future. At the moment the owners are not happy because we have been losing but I think they have been happy with our job over the last three years. Three or four games can change everything."

Mancini does not accept that City's defence of their title has been killed off with three months of the season remaining. If the champions can halve United's 12-point lead by the time of the derby in April, Mancini believes the title race will still be open.

There are five league games to go until the two sides meet at Old Trafford but Mancini recognises City require a substantial improvement on their two recent performances – barely adequate against Liverpool and abject at Southampton – to make any kind of inroad. "It is important to win, win, win," he said.

Mancini added he did not regret his outburst against named individuals who had capitulated at St Mary's, although he said he had been angrier as a manager than he was last Saturday night.

"I think the players know they didn't do their job at Southampton and sometimes it is important they take responsibility," he said. "It is sometimes better that way.

"I don't think a team of our quality should play like that. Yes, we can lose when our opponents perform better than us but we shouldn't have lost like that. A team like Manchester City should be trying to score, score, score."

It says something for the importance Mancini attaches to the FA Cup that apart from Joe Hart, who will be replaced in goal by Costel Pantilimon, and the injured Gareth Barry, City will be at full strength against Leeds. As a player or manager, Mancini has won 11 domestic cups. A 12th cannot come soon enough.