Peterborough boss Graham Westley accused his side of 'naivety' following Tuesday's 3-2 defeat by Wigan.
The League One loss was only Westley's second in six games since taking over.
"Young players will make mistakes, and at both ends we made mistakes. The important thing is young players learn from their mistakes," said Westley.
"While we can look at naive defending for the first couple of goals, we can also look at a performance with great character, quality and desire."
Posh were two goals down after 15 minutes against the Latics after goals by Yanic Wildschut and Will Grigg.
And Westley said his players need to learn some of the darker arts when it comes to defending.
"Young defenders are schooled in academies these days to pass the ball, not in the old fashioned habits of defending," he told BBC Radio Cambridgeshire.
"Yes, you want to own the ball in a game of football and get up to 60, 70, 80% possession, but there's always going to be some defending to do.
"Part of that is making tackles, regaining the ball and we were a little bit naive and too nice in the way we were trying to get the ball back."
Westley brought on Souleymane Coulibaly in the 80th minute, and he made an instant impact to bring Posh level, but Max Power scored a minute later to seal the points for the visitors.
"When you're behind you can afford to take risks, you've got nothing to lose," said Westley of his change.
"We played with a real sense of purpose and endeavour and made the change to bring on an extra forward in Solly, and the change worked well; it was a second half that we won.
"But unfortunately in the first half and first 20 minutes in particular the game got away from us and gave us too much of a mountain to climb."