The Brazilian goalie left the Citizens Champions League match against Atalanta at halftime with a thigh injury.
“He is not able to play. I don’t know how long he will be out for. Sunday, he cannot play,” said Guardiola.
“We have another top keeper. We won the Carabao Cup and FA Cup thanks to Claudio. He is an exceptional goalkeeper.”
Claudio Bravo will start in goal at Anfield. The Chilean was sent off in the Atalanta match leaving right-back Kyler Walker to play in goal for the last 15 minutes of the match. Walker made one save off a free-kick, keeping a clean sheet and winning plaudits from his coach.
Van Dijk and Henderson fit for Reds, Silva out
Liverpool captain Jordan Henderson will also be available for Sunday’s clash. He returned to training after missing the past few days with an illness.
City will be missing club captain David Silva, Rodri, and Zinchenko while Sane and Laporte are long-term absentees.
Guardiola's side will be looking to claw their way back into the table — Liverpool sit six points ahead of last year’s Premier League title winners.
“I don't know. In November, it [title race] never ends. We still have a lot of games to play, we have to fight until the end,” said the Spaniard.
“But if we lose, it will be more difficult, they lost just one game last season and none this season, so it would be difficult.
“Anfield speaks for itself, but it is more for the quality of the team and what they do. Right now it is the toughest stadium in Europe.
“I like it, I love it. This is why we are involved in this business, to play in these games and stadiums. Liverpool are a real complete team, as a club, organization, players. We need a rival like this after winning back-to-back titles.”