Manchester City star Bernardo Silva slammed his side's display in the defeat to Manchester United at the Etihad.
The Citizens missed the chance to move within six points of Premier League leaders Liverpool after losing 2-1 to the Red Devils on Sunday evening.
As a result, the defending league champions have only won one of their last 11 matches across all competition.
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[['It's not one game, it's a lot of games lately," Silva told Sky Sports.
"We have to look at ourselves. You can say oh it's a bit unlucky, no. It's the decisions you make. Today in the last minute we played like under-15s.
"We don't want [mistakes] to happen. It's a bit frustrating because if you look at the game until 86th minute there was only one team that could win the game.
"Then from a corner for Man City, you leave a centre back, Ruben stayed, but we end up with the ball at our keeper. There's no excuse for that.
"When it happens in 10 games, we have to look at ourselves and see what we can do better.
"There needs to be communication for us to play short or to keep the ball in the corner or something. At least if the ball ends up with one of our midfielders, just put it in the corner. Not put yourself under pressure.
"It's not just the pass from Matheus to the goalkeeper. It's everything, how the ball ends up from Ruben [Dias] to Matheus [Nunes] and Kyle [Walker] we have to do better. Be more experienced, smarter, at this level even if you're better than the opponent. You deserve to lose the game.
"It's quite normal that we're not very happy at the minute. Not just this game but the last month.
"We have to do better individually and collectively because it's not the standards of Manchester City."