Manchester City boss Manuel Pellegrini has admitted that he is at a loss to explain his side's stuttering form after they were beaten 2-1 by CSKA Moscow at the Etihad on Wednesday evening.

Yaya Toure and Fernandinho were sent off in a game that leaves City's hopes of qualification hanging by a thread in Group E, and the Chilean coach said that he was baffled by his players' display.

"It is difficult to understand why we played so bad," he told Sky Sports News. "In the beginning we were so nervous and gave away so many passes. We gave them two goals and really we didn't play.

"It's difficult to know why we have so many low performances from important players. We are not changing nothing [tactically]. It is a strange moment.

"I don't think it is just the Champions League, in the last few weeks we are not playing as we normally, but we must find the reason because we are not playing [the right way]. It is a crisis of confidence of course but we must find a way [to improve]. You must never think that you are out if mathematics say that you're in."

City must win both games against Bayern Munich and Roma to have any chance of scraping through into the last 16 of the tournament.