De Bruyne, who is fully vaccinated, caught the virus after returning from international duty.
The 30-year-old was on the scoresheet as Belgium closed their 2020 FIFA World Cup qualifiers with a 1-1 draw against Wales on Tuesday.
De Bruyne will now have to isolate for 10 days and will miss Sunday’s Premier League game against Everton as well as Wednesday’s UEFA Champions League duel with Paris Saint Germain at the Etihad Stadium.
Guardiola said: "Unfortunately, Kevin got a positive test for Covid in Belgium.
"He will be isolated for 10 days."
The former Barcelona manager added: "Forget about fitness, forget about momentum. Now he is positive and now he has to recover well. The human being is more important than anything else.
"When one person is positive, we have to be careful because still people are dying during the pandemic. He was vaccinated so now he is more protected and hopefully the symptoms will be minor.
"When he comes back and is negative, we will start again. He will come back as soon as possible.
"But there is no concern about the rhythm or what we are going to miss. The person is more important.
"We have to help him and hopefully it goes well."
De Bruyne has scored three goals and provided two assists in 14 appearances across all competitions this season.
