Pep Guardiola made the stark admission that he is "not good enough" as Manchester City manager after Manchester United produced a stunning late fightback to seal a 2-1 derby win and inflict an eighth defeat in 11 games on the crisis-hit champions.

City midfielder Phil Foden accused his team of "youth-team defending" after the game, while Bernardo Silva said his side "played like the Under-15 team" at the Etihad.

But with City dropping to fifth place in the Premier League, nine points behind leaders Liverpool who have played a game fewer, Guardiola said that he is now no longer good enough for the club, just a month after signing a two-year contract extension as manager.

"I'm the boss, I'm the manager and I'm not good enough," Guardiola said. "I have to find a solution, it's as simple as that. I'm not doing well, that's the truth.

"It is what it is. What can I say? We cannot blame this player or that one, it's not that. It's the season, a tough season.

"We didn't play our best. We are not our best and we struggle a bit. This is 8 in 11 now, it is not normal, something is not right.

"It's getting worse and worse. I have to find the solution. So far I didn't find it."

City's run of results is now the club's worst since 2003, when the team won just once in 18 games. And the manner of the defeat against United, with the Reds scoring twice in the final moments with a Bruno Fernandes penalty and Amad Diallo winner, left senior players questioning City's performance.

"It was youth-team defending," Foden told the BBC. "It seems to be the story at the moment I don't know what happens but we switch off and they score two goals."

Meanwhile, midfielder Silva said City deserved to lose the game.

"We deserved what happened," he told Sky Sports. "At this level a game or two is unlucky. We can't say this is lucky or unlucky -- 10 games it's not about that.

"It's not one game, it's a lot of games lately. We have to look at ourselves. You can say oh t's a bit unlucky, no. It's the decisions you make. Today in the last minute we played like under-15s."

Up next for Guardiola and City is a Premier League match with Aston Villa where they will once again try to get back on track.