It’s the easiest thing in the world now to say get an experienced keeper. If he isn’t good enough you can say “I told you so” and if he is good enough you can say “Butler was lucky, he turned out ok”.
I’m not going to write him off based on trophy matches and friendlies, has he ever played behind the same defence in any game for us ? It’s all makeshift and trialists every time.
Give the lad a chance and some support.