The Sun says the Belgian international will undergo a scan today after going down in the 81st minute of City's tenth straight win of the season at Swansea City.
And manager Pep Guardiola is not optimistic of having his star forward available for Wednesday's Champions League trip to Glasgow.
Guardiola said: “I think De Bruyne is injured. From the way he reacted, I think it's a muscular injury.
“I don't know how serious it is. I am not a doctor. Tonight we travel back to Manchester City and tomorrow the doctor is going to see what the problem is.
“It's a pity that this has happened because Kevin is an important player for us. But that is why we have a big squad, so everyone can help us."