~Snip~
The truth is that once Manchester City get their form back, it is possible they will focus on both the Champions League and their domestic league. However, if Guardiola notices that they are still in average form, he will definitely prefer to focus more on the Premier League so they can finish in a better position in the league table, ensuring Manchester City qualify for next season's Champions League.
Now the question arises, when will they return to their best form?
Currently City are like toothless lions who are having difficulty beating their opponents, they were not even able to beat Everton, let alone when facing a stronger team in the UCL. If Guardiola is able to improve his squad after taking advantage of the January transfer window, he must focus more on the domestic league to be able to compete again in the top four. I'm not sure City can survive much longer in the UCL, they will definitely lose when facing the favorites.
I don't think it's right to say that they will definitely lose. Because we can't know these things before the match is played. Any effective match can change the fate of the match. For example, a red card that can be seen by the opposing team will put the opposing team at a great disadvantage. Manchester City has not been successful lately, yes we know that, but maybe they will be better in the future under Guardiola. Guardiola currently has a period of rest ahead of him. I think he has the capacity to use this period in the best way and turn the team into a more energetic and well-playing team.