Goalkeeper Petr Cech says Chelsea's players must eradicate their mistakes if they're to recover from defeat to Bayer Leverkusen.
The Blues now require either a goalless draw or victory over Valencia to secure qualification to the last-16 of the UEFA Champions League, following a late defeat in Germany.
Andre Villas-Boas' side's defensive fallibility was exposed yet again at the BayArena and Cech, whose error of judgement allowed Leverkusen a route back into the tie, says individual errors must be cut out.
"There are no excuses," he said. "We need to look first at ourselves and then we can criticise the other people because we put ourselves in the situation where we were 1-0 up and we could have killed the game off.
"Then there would be no discussion whatsoever about things that were happening in the game. We have to take it like that and make sure that this is the last time it happens.
"The manager is not on the pitch, we are on the pitch and we are making mistakes.
"He cannot do anything about individual mistakes while he is standing by the bench. So the players are to blame and we know it and we try to make things happen and change. It is not easy but we keep going."
Manuel Friedrich's stoppage-time header handed Leverkusen the decisive late win, and Cech is frustrated Chelsea have put themselves on the brink of elimination.
"It [the header] was too good. I tried to reach it but I couldn't and that was the reason why the goal went in," he continued.
"We have put ourselves in a difficult situation because we could have had qualification done a month ago but that is the way it is. We play at home and it is up to us to deal with the situation.
"We are one of the top teams in Europe and this is not a situation we want to be in. The reaction of the players is that we can show on the pitch that we really mean what we say."