City were hoping to begin the campaign on the right note to try and challenge for the Premier League title.
But they have stuttered in league games, and find themselves in the bottom half of the table for now.
Bernardo hopes they can regain their form, with the latest poor result a 1-1 draw with West Ham United.
"The truth is that we haven't started the season well at all, we have to do a lot better than two Premier League games won out of five," Silva told L'Equipe.
"It's true that we had a lot of injuries, and players who get injured again and again. But that can't be an excuse with the team we have.
"I don't have a good explanation, we have to talk among ourselves in the team, with the coach, because if we want to win a title this season, something must be changed.
"We have the impression of a team that lacks punch, taking offensive responsibilities. All the teams know how to play. And we find ourselves against teams that do not want the ball, they are only waiting for the counter. At the start of the season, we didn't manage to be dangerous, to create a lot of chances, or to be effective."