De Bruyne has a big chance of being played by Pep Guardiola in this match and if he is currently in a fit position it will provide a big advantage for Manchester City.
There is no chance in hell that De Bruyne is available for this game, he hasn't even started training yet, nor running, KDB is still some weeks away from returning to training, and when he does return to training, City will have to be careful with him, he isn't just going to be thrown right back into the action, he would be slowly integrated back into the team to avoid a recurrence of the serious injury he sustained on the first day of the EPL season.
That being said, City have coped very well without KDB, Julian Alvarez has replaced him in that role, and he has done it so well. This is a big game against Liverpool, but City are at home and they are so hard to beat at the Etihad. The first game after an international break can be somewhat tricky, the players need time to find their rhythm again, some might return injured or tired; thus i hope we can still get a cracking game.
After the international break, Manchester City may have to prepare to face Liverpool without some players like Stones and Ederson. I know there are some conversations forming around De Bruyne's return with Guardiola hinting that that might be soon. There are other players who can still perform better in Debruyne's absence, so I don’t see any reason for Guardiola to want to rush him. I think he underwent surgery on a recurring hamstring injury, and Pep has said there are no plans to rush de Bruyne back into his side. De Bruyne had been managing the long standing hamstring complaint during Manchester City’s run to the Treble last season and didn’t have a proper pre-season.
They have a big squad that can handle any kind of injuries. If he continues to nurse his injury till mid December, then I expect De Bruyne to return to the Manchester City fold in the New Year, so there are still a few months to figure out Guardiola's next steps.