Branislav Ivanovic reflected on what might have been against Maribor and admitted Chelsea must improve to emerge from Liverpool on Saturday with their unbeaten record intact.
Jose Mourinho was frustrated at yet another insipid performance from his side - following the below-par wins against Shrewsbury and QPR - as the Blues had to battle from behind to draw 1-1 with Champions League Group G minnows Maribor in Slovenia.
Chelsea, who are unbeaten in 16 games this term with only four draws, have little time to digest a performance which could have been a win had Eden Hazard converted a late penalty for the second successive game.
That would have secured qualification for the last 16 with two games to spare, but now the Blues must forget Europe and swiftly refocus on domestic duty as they travel to Anfield on Saturday lunchtime.
"We know how our performance has to be to get the points from Liverpool away," Ivanovic said.
"I think if we play against Liverpool as we played against Maribor, we know it is not possible (to get any points).
"Of course this was a warning to the team and this is good.
"We should have finished the group, but now it's too late and we have to think about the next games in the Champions League."
Chelsea must now wait to seal their progress until at least the November 25 trip to Gelsenkirchen, where their European Cup-winning boss Roberto di Matteo is now in charge of Schalke.
Didier Drogba, who scored the decisive penalty in the May 2012 final with the last kick of his first spell, made his 100th European appearance in Slovenia.
"Not the best one," the 36-year-old Ivory Coast striker, who remains confident of progression, told Chelsea TV.
"We came here for a better result, but okay, at least we didn't lose. We can still win the group."
Immediate matters turn to Anfield, where Chelsea won 2-0 in late April to derail the Reds' hopes for a first English championship in 24 years with a resolute defensive display featuring ruthless counter-attacks.
Ivanovic has no concerns about the turnaround.
"We still have two days to recover - this is normal," he added.
"It's not the first time we have had to do that. We are professional and have to do a lot of things to be ready for that game.
"It's massive - one of the crucial games for us. For this kind of game you always have to find extra motivation and it's not about tiredness or fitness."
Mourinho afterwards bemoaned complacency and the officials for ruling out a Diego Costa strike for offside, when it appeared to be a legitimate goal.
Costa had been called off the substitutes' bench, alongside Oscar and Ramires, when Mourinho had hoped to keep the trio fresh for Liverpool.
It was difficult to comprehend how Chelsea struggled to cope with a team they had beaten 6-0 two weeks earlier.
Ivanovic insisted it was a timely sign that, despite their at times scintillating start to the season, Chelsea cannot underestimate any opposition.
"When you look on the positive side of these games, this is a reminder," the Serbia defender said.
"It is a warning against complacency. We can't be relaxed. We have to learn from every game.
"When we go into a match relaxed and don't play for 90 minutes with our level of performance and intensity, we struggle to get results.
"We have to be smart and play every game for 90 minutes."
Liverpool boss Brendan Rodgers was critical of Mourinho's methods following the most recent contest, saying anyone can coach a team to defend and that Chelsea "parked two buses".
Nemanja Matic, who did not expect Liverpool to toil as much as they have done this term, insisted there is an art to defending, but that the Blues offer a different threat this term.
The midfielder said: "Many teams this season have tried to park the bus in front of the goal against us, but we win.
"It's not easy. If you defend, you have to know how to defend. In that game (in April) we showed we have quality.
"Now is a different story, and we play a different way.
"Nobody's happy when you lose a game, and they weren't happy after that match.
"I am surprised to see where Liverpool are, of course. They have a good team and I didn't expect that they would be in this position.
"But we are ready, we are first in the table and we want to stay there."