Pep Guardiola insists his side have to play the “perfect game” to overrun a three goal deficit from the first leg.
Guardiola insists the tie is not over and said his side can use the challenge as inspiration, he understands how difficult the task is.
“Of course, to go through you have to make almost the perfect game – create chances, be clinical and concede few chances,” Guardiola said.
“All the conditions have to be perfect to go through.
“But you have 90 minutes and in football everything can happen. We are going to try and we will see.
“We have to score the first one, then make the second one. We will see. We need the momentum.
“We have to focus on what we do. If we concede a goal, don’t give up.
“We did it many times, in a short time we can create chances and after you have to be clinical. And if we are not clinical, okay, next one, next one, next one.”
The Blues Boss admits he still had belief in his “extraordinary” side.
“To reach the semi-final would be the second time in our beautiful history,” he said. “I don’t have to talk about how beautiful it is.
“They show every single game what they want to do. I know you judge results, but performance? My team is extraordinary. Exceptional.
“It is a joy to be manager of the team, I am so delighted.
“After the goals against United, we still create chances. I am so delighted to lose the way we did.