The judgement you made is that we should not judge players on only 45 minutes of play.
In that case, why did Potter give all his players a maximum of 45 minutes?
What is the minimum number of minutes you can play before a player can be judged?
Friendlies primarily are about fitness, integration of new players and trying different shapes both attacking and defending. In terms of judging whether a player will succeed, this will not be done in 45 minutes.