Their midfield was key last season and if we now think about who is left of that midfield, both are gone. Gundogan and De Bruyne. Since the two controlled the whole Manchester City game and also scored goals and gave countless assists, it doesn't come as a surprise that now when both of them are absent the game is much worse than it was last season. I think this is probably the difficult task ever for Guardiola to find two successors for Gundogan and De Bruyne who are able to manage the Manchester City game on the same level.
Kevin De Bruyne is arguably one of the best players in the Premier League. In a few years, he will undoubtedly be remembered as one of the icons of the Premier League. İlkay Gündoğan was also a midfielder who scored a lot of goals despite being a midfielder. Especially in critical moments, he could come on the scene and change the fate of the match. He was very cool and very professional. Kevin De Bruyne suffered an unfortunate injury and Manchester City were helpless. But it was clear that Ilkay Gundogan would leave the team. I think Manchester City should have made a good signing to replace him. They are a bit wrong in this regard.
Maybe it's true, Manchester City failed to get a good attacking midfielder to replace De Bruyne and Bernardo Silva in their absence. However, several other players such as Phil Foden and Kovacic seem to be able to get that role for a while, but it is clear that Manchester City needs the best attacking midfielder in this transfer market.
I'm not sure who they are targeting, but Manchester City want someone of the caliber of Bernaro Silva and Kevin De Bruyne in their squad. Pep Guardiola know that, but players like that are very hard to find. In time, Manchester City will lose Bernardo Silva and Kevin De Bruyne. They cannot remain silent and must immediately find a player who can replace that role, otherwise Manchester City's competition and dominance in the Premier League will collapse.