The City chief described the fact that his side didn’t win its fifth game in succession as ‘incredible’.
And he berated his charges for lack of concentration and not staying as strong as they should have done.
City led through a Sergio Aguero double but were then surprisingly pegged back and lost ground at the top of the table.
“When it was 2-0 we thought the game was finished and you cannot do that,” declared Mancini.
When you are leading 2-0 it is important to control the game
...Roberto Mancini
“It is incredible that we lost these two points. Of course you cannot win every game away from home but this is one that we should have won.
“We should have scored more than one goal in the first half just like we should have scored more than one against Wigan in the first half when we were similarly dominant.
“We have to learn the lessons. We did a foul throw for the first goal and the second one should have been a free kick to us because Dzeko was fouled but that is football.
“I am frustrated because I believe that we should have won the game. We gave away stupid goals.”
Mancini also rued the lack of senior fit midfielders which forced him into minimal changes from the side that drew with Napoli in the Uefa Champions League.
And he defended his decision to remove playmaker David Silva when the score was 2-1 in his side’s favour.
“I thought about more changes but I don’t have James Milner and Nigel De Jong available,” he said. “We were tired after the Champions League game and David has played all the games. We needed some fresh legs in midfield and either he or Samir Nasri had to come off.”
Mancini confirmed that he would now rest star names for the Carling Cup tie with holders Birmingham on Wednesday night.
“We play again in three days and it is impossible that all the same players can start again,” he concluded.
