England coach Gareth Southgate feels their 5-3 defeat of Kosovo was a good test for his young players.
Although the hosts recovered to go 5-1 up, they conceded two quick-fire goals in the second half - including one from the penalty spot after a foul by Manchester United's Harry Maguire.
Asked if the individual errors were a lack of concentration rather than anything more fundamental, Southgate said: "I think that is something that we have to consider over a period of time because there were obviously mistakes that were concerning, really.
"Whether it was the intensity of the game, whether it was the pressure, I don't know. We have got to reflect on that but they were such basic errors, really, that you have to learn from.
"What I would say is generally as a team, they recovered from those errors, although there is nothing worse than a losing lead for making a team feel uncomfortable.
"I think that generally speaking, they took control back of the game, and even the likes of Mason [Mount] coming on at the end, that is not an easy position for a young player to go in but we know he's got the maturity to play the role really intelligently and [he] took the ball under pressure, pressed intelligently.
"So, actually it was in many ways a better experience than strolling through the game at five, six or whatever, even though we probably all could have done without it. "
