Manchester United No2 Mike Phelan rapped their youngsters over the Carling Cup defeat at West Ham United.
Although Sir Alex Ferguson maintained his policy of never criticising his players in public, claiming United's youngsters would learn from the chastening defeat, his assistant was frank in his assessment.
"Some of the defending was naïve," said Phelan. "There are lessons to be learned from the defending point of view with individual players and hopefully they will take something from that.
"You can learn from defeats and we need them to learn quickly. They are quality players but they are young and they are going to make mistakes.
"It's how they deal with those mistakes and how they react. So we'll be looking in the next few days to see what character they've got and whether they can step up to the plate next time."
