Delio Rossi concedes it's very difficult for Palermo to qualify now after their “naive” sending off in Moscow.
The Rosanero were leading 1-0 thanks to Massimo Maccarone, but Antonio Nocerino's red card just half an hour in paved the way for CSKA's 3-1 victory.
“We had started well and gone in front, but after that dismissal everything changed,” said the Coach.
“We were naive and inexperienced, so at this level Moscow quite rightly punished us.
“We cannot keep playing with 10 men for second bookable offences. This has to act as a lesson to the team and valuable experience, because this is what it's like at international level.”
Javier Pastore was suspended for this game, as he was sent off the last time these teams met a fortnight ago.
With Sparta Prague winning 3-1 away to Lausanne, Palermo are now four points adrift of second place in Group F. CSKA Moscow have already qualified with a 100 per cent record.
“Now it's very difficult for us to reach the knockout round. We need to get six points in the remaining two games and hope the other sides slip up.”