Gareth Barry has admitted that Manchester City have not played to their potential in the Champions League and said the English champions have been "found out" by Europe's finest.
City have only taken one point from their first three fixtures, with defeats to Real Madrid and Ajax sandwiching a 1-1 draw with Borussia Dortmund.
They face the Dutch champions again at the Etihad Stadium on Tuesday knowing that another loss would end their hopes of progressing to the last 16.
Barry said: "It is quite clear that we have not produced our best performances against the quality of opposition that are in the Champions League and when it comes to these games when you're not producing your best you get found out. That seems to be what has happened.
"You know what you will face in the Champions League, it is going to be a real high standard and a different style of football. We need to adapt to that a little bit better. If you don't perform to the height of your abilities, the way you can play then you do get found our as we have seen."
The England international believes the first game of City's campaign was a turning point. Roberto Mancini's team twice led in the Bernabeu before being condemned to defeat by Cristiano Ronaldo's last-minute goal.
He explained: "If we had held on against Madrid, it would have put us in a different position. We would have gone into the other games with a different mindset but it did not happen and that's no excuse for the performances after that."
Mancini has said that publicly that City cannot win the Champions League but Barry revealed the Italian has been more optimistic in private.
He added: "After the Ajax game, when everyone was disappointed, he has still instilled us with belief, that if we win the three games, then we can go through. As players we believe in that too. While it is still possible to qualify, that is our aim."
While City are often accused of having too many egos, Barry denied there are divisions in the dressing room.
The midfielder is one of the lower profile and less demonstrative members of the City side but said team spirit is apparent in the way the players go about their work.
He said: "Whenever there is a defeat these things can be thrown at the team. It was clear that we did not perform to the best of our abilities. It was not down to a lack of effort from the team or a lack of team spirit. It is clear, and last season showed it, that we have that spirit.
"If you go in the dressing room, we are not high fiving every five minutes or having long conversations. The team spirit is being professional and doing a job on the pitch together and that is what we feel we have got. We try to do that, perform and run for each other, the fans and the manager. That is team spirit."