Pep Guardiola has taken the blame for Manchester City's FA Cup final defeat by saying he got his game-plan wrong against Manchester United.
United won 2-1 at Wembley on Saturday thanks to goals from teenagers Alejandro Garnacho and Kobbie Mainoo.
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City missed a number of chances in the second half before Jérémy Doku pulled a late goal back, but Guardiola insisted afterwards the defeat was his fault.
"For my decisions, we were not in the right positions to attack them," Guardiola told a news conference. "My mistake. My game plan was not good. Tactically, it was not good. I was not good, today."
After going 2-0 down in the first-half, Guardiola made changes at half-time by bringing on Doku and Manuel Akanji. Julián Álvarez was also introduced early in the second half at the expense of Kevin De Bruyne.
"You plan a game for different positions but it didn't work," Guardiola said. "Even with that, we arrived two or three times in the final third and byline and made nothing from crosses.
"They made one goal from one shot and the goal from Mainoo and no more than that. Always, when we play against United we have the control and we created in the second half but we were not able to do it.
"The second half was much, much better. We were more intense, in part because we were 2-0 down and had nothing to lose. It was a tight game."
City's players were given permission to celebrate their fourth successive title at a Manchester restaurant on Sunday.
The squad were also given Monday and Tuesday off before returning to training on Wednesday, but Guardiola rejected a suggestion that City were under-prepared to face United.
"No, completely the opposite," he said. "They were completely focused and how they reacted was so good. "Congratulations to Manchester United for winning the FA Cup. I think my game plan was not good."