Kevin De Bruyne tested positive for COVID-19 during international duty with Belgium.
The Belgian midfielder is currently undergoing self-isolation for 10 days and will also miss the Champions League clash against PSG.
Although De Bruyne would be a huge miss for the Citizens, Guardiola added that his only concern is about the playmaker’s recovery.
The Spanish manager added: “Forget about the fitness, forget about the momentum. He is positive. He has to recover well and try and be healthy. The human being is more important than anything else.
“When one person is positive we have to be careful because people are still dying. He was vaccinated, so now he is more protected. Hopefully the symptoms will be minor. When he comes back negative, he will start again to train with us as soon as possible.
“We are not concerned about the rhythm or what we are going to miss. The person is more important.
“When someone gets a positive you have to be careful. We have to help him and hopefully it goes well whilst he is isolated.”
Foden is doubtful for Sunday’s clash.
Man City forwards Jack Grealish and Phil Foden sustained injuries on international duty with England.
Guardiola said that Grealish is ruled out for Sunday’s game against Rafa Benitez’s side, but Foden’s fitness would be assessed prior to the game.
Guardiola added: “Jack is getting better. Phil Foden came back with a problem in his leg.
“Jack I don’t think [will be available], Phil maybe.”
Man City are second in the league table with 23 points, trailing leaders Chelsea by three points.