I am not convinced that the City players could be distracted by the upcoming game against Real Madrid. There is Pep Guardiola who understands like nobody else how to direct the focus of his players to the single task that is ahead of them and then there is this endless experience playing on the maximum level almost every single game. This may apply to less experienced teams and players, but I don't think that the majority of the City players could lose focus or are less focused than they normally are because there is this clash against Real waiting for them. But still Arsenal has a chance to win the game. City is amazing, but they are not magically protected from losing games.