This is maybe where Dele is going wrongI am not so sure.
This Haller guy has physical ability, but from what I saw him, he tried too hard to become a poor man Zlatan.
Zlatan has the productivity and as importantly, the big brother influence in the dressing room, that plays a part in having managers let some mistakes/ wastefulness on the pitch slide.
For that role, I don't think Mourinho like wasteful forward, who doing flick, and back heel just for the sake of it; which this backheel merchant Haller is.