City's chances of finishing in the top four were hit by the 3-0 reverse at Anfield on Monday night and afterwards Mancini took the blame for the defeat.
"I'm disappointed with myself because I think I made a mistake," he said.
"It was my fault. Not with the players because the players played 100 per cent. Probably I made a mistake in the last two days but I know why. I did three changes and brought in three fresh players. Our focus was not good.
"It probably was my mistake because we prepared for this game not very well. But I think it is better to lose one game 3-0 than three games 1-0."
Mancini was coy over exactly what "mistake" he was referring to but did admit bad-boy striker Balotelli, who came on for the injured Carlos Tevez in the first half but was then substituted himself late on, turned in a disappointing performance.
"He didn't play well," the City boss added sharply when asked about the striker's evening.