The injury on KDB is really going to affect the Citizens in tonight's game against Seville and even in the EPL fixture against Newcastleon Saturday. We all saw how Manchester City played against Arsenal without KDB, they were horrible but as soon as the man De Bruyne was introduced the game changed in their favor. But I don't see anything special about City without Kevin De Bruyne as of now even with the man Bernardo Silva is not enough to make a change in that team. Is best Pep get someone to fill in that gap or else City won't be as dangerous as of last season.
It is difficult for other players to replace De Bruyne role in the Man City midfield, but Pep Guardiola definitely has a strategy to maximize other lines in order to win the match against Sevilla. This means that Pep still has alternative players who can fill the void. Sevilla has just received defeat in their opening match in La Liga this season, my prediction is that Man City will play as usual by dominating the game.
Seeing the conditions of the two clubs, I think the final score in the match will not be too much, maybe 2-1 for Man City victory.
I don't think losing De Bruyne has had much of an effect on Manchester City's game as a whole. Pep Guardiola, of course, has prepared several other schemes that keep his team stable. Mateo Kovacic is the right alternative to fill that void and he is also a player who is quite experienced so I think Kovacic will be able to give maximum role in midfield. City will certainly win against Sevilla in the Super Cup Final, I have absolutely no doubts about the capacity of Manchester City under Pep Guardiola.