Roberto Mancini has criticised his Manchester City squad for failing to reproduce their title-winning performances of last season, demanding an immediate improvement heading into the final 12 Premier League games.
City now lie 12 points behind Manchester United at the top of the table after Sir Alex Ferguson's men's capitalised on their rivals' mistaken-ridden 3-1 defeat to Southampton with a 2-0 win over Everton.
And Mancini has called on his players to step up and take responsibility, claiming they should question their contribution to the team.
"When you play football and you are a top player, you should take your responsibility, always," Mancini told reporters. "It's not always the fault of the manager.
"The players should take responsibility - if they have big balls. If not, they can't play in a top team."
Mancini did, however, recognise that his side’s first-ever Premier League title defence was always going to be difficult and lamented a lack of transfer activity during the summer.
"For a team like us which has won the title, won the FA Cup, won the Charity Shield after 38 years, it's normal the year after as champions could be difficult," he added.
"But probably because we did some mistakes in the summer and we didn't improve our team. But now we have good players and I think we shouldn't do a match like this.
"No, no, now we can do nothing about that [failure to capture summer targets]. But in this moment we should do more because we have 12 games, we should get the maximum points we can get, we have the FA Cup and this season is not finished.
"I don't want to see a player like we saw [against Southampton]. A player who plays like that should stay at home, not even be on the pitch.
"Usually, we play well and even when we don't play well we put everything on the pitch but we didn't even for that. That's the problem. Only this.
"They played better than us, they deserved to win, congratulations to Mauricio Pochettino, to Southampton, but I am very disappointed with our performance."