Defeat means that the city is based on Villarreal, who have not received one point in their group games so far, to prevent the Italians in their tracks while Mancini tries to overthrow the Leaders Bayern Munich in the final round of group matches in December.
Speaking to Sky Sports after the match, Mancini has been gained. "I think we should believe that because it's not clear that Villarreal will not receive points against Napoli]," he said.
"They can win or a draw but I do not think they'll end up with zero.
"We want this because it is our mentality, but now, just because we lost this game, I do not think it is complete. In the Champions League this can happen, but this is football stone and we have a game. Never say never. "
With the game slip away in the second half, some questioned why Mancini waited until 81 minutes to bring Sergio Aguero from the bench, but the management and protection of their decisions are not at risk all out on attack.
"We do not want to leave any space. If we assume a target Tuesday, it has been completed. In the last 20 minutes, we had four or five chances but their keeper is excellent. "
The Italian coach further expressed his satisfaction with the amount of chances his side created, but not impressed with two goals they allow.
"I think we did not deserve to lose this game, but, at the same time, we should think we can score in every game, at least three or four. But in the Champions League, if you acknowledge two goals, two stupid goals ... [you at risk of losing].
"After we equalized, we've got two chances to score to make it 2-1, and it is strange that we acknowledge that the goal after 10 minutes of the second half].
Mancini admits he was not sure exactly what to say to the players before their showdown in vain their ability to Bayern on December 7.
"I do not know," he admitted when asked how he would restore the confidence of his players.
"I think for us, which is the first time we played in the Champions League, but I do not think Villarreal will lose a game. I do not see why they can not draw or win."
Failure to see the city on six points in Group A, two points from Napoli, but Villarreal failed to record any point at all to ensure so far Mancini's men will drop into the Europa League if they do not overthrow their deficits.