Manchester City manager Manuel Pellegrini said that his team were suffering "a crisis of confidence" after they were left on the brink of Champions League elimination by CSKA Moscow.
City had ended a three-game winless run by beating Manchester United 1-0 on Sunday, but they produced a strangely insipid display on Wednesday in a 2-1 home defeat by the Russian champions. (Also read: Man City on brink of early Champions League exit)
Seydou Doumbia scored both goals for CSKA at a cold and misty Etihad Stadium, either side of a free-kick by Yaya Toure, who was sent off in the second half along with team-mate Fernandinho.
City now trail CSKA and Roma by two points ahead of their next game at home to already-qualified Bayern Munich and with their fate no longer in their own hands, Pellegrini admits the English champions have lost their way.
"It is a crisis of confidence," said the Chilean, who is bidding to prevent City succumbing to a third group-stage exit in four years.
"It is difficult to know why. It was such a low performance from important players. It is a strange moment. It is not just this competition. In the last two weeks, we are not playing.
"I don't understand, why but we must find a reason because we must arrange the situation."
As well as sending off Fernandinho, for two bookable offences, and Toure, for shoving Roman Eremenko, referee Tasos Sidiropoulos failed to show a second yellow card to CSKA midfielder Pontus Wernbloom in an apparent case of mistaken identity -- instead booking Sergei Ignashevich.
Sidiropoulos also waved away a strong late penalty claim by Sergio Aguero, who he had earlier booked for diving.
But while Pellegrini felt that Sidiropoulos had made "mistakes", he said the Greek official's display was a red herring.
"I don't want to analyse the referee's decision," said the former Real Madrid coach, who felt the red cards suggested his players had been "nervous".
"He referees the game and must decide if they are red cards or they are not red cards, or if it is a penalty or if it is not a penalty.
"It is more important for me to analyse why we are not playing in the way we always work."
Despite City's perilous position, Pellegrini vowed that his players would not give up hope.
"You have the mathematical option to qualify, you must fight for it," he added.
"We must first try to play against QPR, then we have the international break, and then we are going to try to qualify for the next stage. It is more difficult, but it is not impossible."
Pellegrini also revealed that captain Vincent Kompany will undergo tests on Thursday after limping off at full-time.
"I don't know at the moment if it is just a kick or we will see if it is some problem with his calf," he said.
CSKA coach Leonid Slutsky praised Doumbia for his match-winning turn, which came two weeks after the former Ivory Coast international scored a goal and won a penalty in his side's 2-2 draw at home to City.
"Obviously when he had the first game in Moscow, he could hardly walk, he was limping," said Slutsky, whose side had never previously won in England.
"Even limping he could score a goal and was fouled for the penalty. Before today's (Wednesday's) match he didn't have much preparation because of the injury and he hasn't been training for months.
"Considering all of that, he showed a very high level of skill and he deserves to be treated as a hero."
CSKA's press officer also confirmed that the club's Serbian winger Zoran Tosic, formerly of Manchester United, had been prevented from playing after he entered the country with the wrong kind of visa.