The Norway international was flat for Saturday's defeat at Manchester United.
Guardiola admits Haaland will be needed for tomorrow's Champions League trip to Bodo/Glimt with Omar Marmoush returning from Egypt's Africa Cup of Nations campaign.
Asked if Marmoush will be in the squad for Norway, Guardiola said: "No, I don't think so. I don't know when Omar comes and Erling is going to play. We need Erling and we need all of them.
"Erling is so important for us. We are lucky to have Erling with what he has done.
"We'll see what happens next game. We have to travel to Norway and go in there and see how they recover. Not just physically. I can smell how they feel.
"And after, we continue. We did it last season and we continue this one. We have a lot of important games, every three or four days."