The game and, arguably, the tie, was settled inside 31 minutes at a raucous Anfield as goals from Mohamed Salah, Alex Oxlade-Chamberlain and Sadio Mane humbled the runaway Premier League leaders.
City were beaten 4-3 on Merseyside in January but Guardiola feels their exploits elsewhere – a 5-0 win at home to Liverpool last September, for example – should give them a reason not to give up the ghost.
"In this room I think there is nobody except the guy talking to you who believes we can go through. There are 90 minutes more, we are going to try," he told a news conference, before grouping City in with the other seemingly doomed teams in the draw.
"I believe a lot in my team. They show me many good things in the season. The result is so tough, you cannot deny it.
Echoing a theme from the January loss – the only reverse in England's top flight this term for City, who can seal the Premier League title with victory against Manchester United on Saturday – Guardiola lamented his team losing control for a 10 to 15-minute spell, albeit much earlier in the game on this occasion.
"Our first minutes… it is always important to see how the team is. Did we arrive here a little bit scared? We arrived with a huge personality," he said.
"The problem is they arrived two times, the first one offside, to score two. Here at Anfield, it is always complicated."
Guardiola added: "When you play badly and the opponent is much better than you and it is 2-0 you have to accept it.
"But I do not have that feeling. Maybe tomorrow when I review the game I will say it was a disaster, but I do not have that feeling."