I don't think it's that big of a concern as long as he creates chances and scores goals. He will eventually get some more. I still see him making those passes that only him and Lamela can pull off. Like that flick to Kane against Arsenal, that got wrongfully called offside(not like we have seen that before!).
I do think however that his crossing has been worse this season. I think he benefitted last season from an in form Ade and some late runs from Paulinho. Watching him and Kane, they are much better with the ball at their feet. I can see Mason developing some of those late runs into the box when his fitness gets better. You can say many things about Paulinho, but he was much more of a goalscoring threat than Bentaleb, Mason and Dembele.
I do think however that his crossing has been worse this season. I think he benefitted last season from an in form Ade and some late runs from Paulinho. Watching him and Kane, they are much better with the ball at their feet. I can see Mason developing some of those late runs into the box when his fitness gets better. You can say many things about Paulinho, but he was much more of a goalscoring threat than Bentaleb, Mason and Dembele.