City head into Tuesday’s second leg at the Etihad Stadium trailing 3-0 following last week’s drubbing at Anfield.
If the hosts concede just once against the rampant Reds, they know they will have to score five times to book their place in the semi-finals.
And Guardiola knows the size of the task presented to his side.
“To go through you have to make the perfect game,” the Spaniard said in his pre-match press conference on Monday.
“We need to create chances and concede few chances, and the chances we receive (against) we have to defend well.
“We have 90 minutes and anything can happen. All we are going to do is try.
“We will think about how many goals we score after we get the first one.”
Midfielder Fernandinho insists it is up to him and other senior players to lift a City side who have suffered back-to-back defeats for the first time this season.
Last week’s Anfield humiliation was compounded by a defeat in Saturday’s derby against Manchester United – losing 3-2 to their rivals after leading 2-0 at half-time.
“It was a tough week for us, two defeats in a week but that’s in the past already,” said the Brazilian.
“Our focus is on the second leg against Liverpool and the only way to play good football is to be positive.
“Now’s the time for experienced players to take over and take charge. Of course we know two defeats are not easy but that happens to the best teams in the world.
“What we have done this season is amazing and we have a chance to go through in the Champions League. It won’t be easy.
“They (Liverpool) are a team who fight for the ball and try to keep the players in the middle but we will be ready for tomorrow’s game.”
Guardiola was asked whether his side’s mental state had been affected by their last two results.
“I don’t know but if we are not able to cope with that psychologically it will be a good lesson for the future. It is a test, football like life is a challenge,” he added.
“We have 90 minutes plus extra time and what we have shown this year – even in the last game – we can create a lot of chances in the last few minutes.”