City have won just once in 11 games in all competitions, a run that includes eight defeats. After an unprecedented four consecutive EPL titles, City's defence of their crown looks over before Christmas. Guardiola's men trail leaders Liverpool, who have a game in hand, by nine points.
"I don't have defence, I'm the boss, I'm the manager. I have to find a solution and I don't find a solution," said Guardiola."
The manner of City's latest loss was one of the most damaging as the English champions were headed for a much-needed victory against their local rivals thanks to Josko Gvardiol's first-half header.
Bruno Fernandes converted from the penalty spot to equalise on 88 minutes. Diallo then raced onto a simple long ball over the top to complete a remarkable turnaround. "I am sitting here in the press conference because of what we have done in the past," added Guardiola.