Manchester City can of course feel the absence of De Bruyne in the Champions League as well. However it is the truth on one hand that they are still able to stay strong. Things are going well in the English Premier League these days. They are winning their matches one by one and I don't doubt their performance in the Champions League too.
Manchester City squad is full of talented players. Guardiola can find a solution to his absence one way or another here as well.
De Bruyne is one of the most special players in this squad. He has a wonderful relationship with Haaland. I hope we don't see Haaland getting balls less than before without him. For now he is still doing okay at scoring.
Of course Pep Guardiola is a coach with a new philosophy and has a broad insight into players. He installed Julian Alvarez in De Bruyne's original position. If you saw him in the first game earlier this season. Although at that time De Bruyne did play but in double pifot with Rodri. But it turned out that his hamstring had not healed properly and he only played 23 minutes. Against Newcastle, Julian Alvarez was back in the same position. Even he was able to make goals.