The result leaves City in fourth, three points in front of Tottenham having played a game more.
It was the worst preparation for Saturday's Wembley meeting with Manchester United, which skipper Carlos Tevez is almost certain to miss after the South American limped off with a hamstring problem at Anfield.
Yet Mancini retains an unshakeable faith in his players' ability to rise to the stiffest of challenges.
"I am not worried," he said. "I am sure that we will get to the Champions League and reach the (FA Cup) final.
"I am disappointed with myself. This game was all my fault. I made mistakes in the last two days. I know why. I can't say any more than that."
Source: PA
Source: PA