He was getting caught out of position because of how he was asked to play,and no he is not a very good player,and he is limited defensively but he was also getting pulled all over the place though a lack of help.He is also a very easy target.
I don't blame him. Not his fault he isn't good enough. And tbf to him he doesn't hide.
But Koeman should not have signed him and on his head be it.