You sound like Manchester City will not lose to Arsenal, even though their first eleven are all injured. The Arsenal of this season is different from the Arsenal of last season, and they won against Manchester City at the Emirate Stadium this season. Arsenal is consistent and scores a lot of goals against their opponents. Arsenal is capable of beating Manchester City on Sunday.
Well undefeatable is a myth, Manchester city can defeat arsenal, and also Arsenal can defeat Manchester city. There is no monopoly of victory or defeats. Instead we can discuss the odds in favor of either manchester city or arsenal.
For me, i am stuck between a defeat for arsenal or a draw.