Manchester City's performance against Sevilla in the UEFA Super Cup final seems to be a poor performance compared to last season. Many may say that Sevilla's performance has improved compared to before but I would say Sevilla's performance was not good but Manchester City's poor performance is why Sevilla did so well in the UEFA Super Cup final against Manchester City.
Due to De Bruyne's injury, Manchester City didn't perform as well as they may have. Because of this, it appears that Sevilla performed somewhat better than them.
In the upcoming four months, I'm not sure how Manchester City would perform without De Bruyne. It is clearly clear that De Bruyne contributes significantly to Manchester City. He is the source of those precise passes that Manchester City employs to score goals; without him, the team would struggle to prevail in games. I think It will not be possible for them to remain at the top of the premier league this time.