I was seeing Manchester City as one of the favorite teams to win this season champions league trophy but after I watched Manchester City's performance against Brighton in the Premier League, I don't think Manchester City is ready to compete for the champions League trophy this season unless they are able to improve their performance before the champions league starts and prove me wrong.
Manchester City will still go out to win the champions League this season it doesn't matter how well they do in the EPL this season but the Champions League competition is a different game and they may go all out to improve their performance and if that is done Manchester City will be ready to face other good teams if they are lucky they can get to the finals. City has gained only 3 points in 3 matches in the English Premier League this new season they have a lot of things to improve on if they what to make it to the finals they season.
The Manchester City team that I'm seeing today don't have those super grips they had two or three seasons ago, their performance in the English premier League have shown that they are still trying to get their acts together, even in the last champions league their performance was far from what we expected. But one person I respect in this City situation is Pep Guardiola, his one of the most brilliant Coaches we have in Europe, trust me he can come up with good tactics anytime soon, but for now they are still in the struggling stage.
I see the same thing as you. Man City is no longer the same as it was two seasons ago, especially since Pep squad hasn't fully achieved this level of success. This can be seen in the three matches they've played, with only one win. I believe the source of the defeat is his over risking and overconfidence, discarding players who would have been very good if kept.
Furthermore if you look at Man City current game they're too drawn out the ball is passed back and forth from one player to another, lacking creativity and effectiveness. When the ball is controlled by the opponent and a quick counter-attack, the City players are confused. Pep has a lot to fix in the Manchester City squad, and he doesn't have much time, as after the international break, Man City has tough matches against Man United, Napoli, and Arsenal. If Pep can get through all of this with a positive result, it will be good for Man City to bounce back and will be considered again as a strong contender in the UCL league.