I'd hold off judgment until he's got 19 more appearances for us. Because given what he showed Saturday, it's quite possible Niasse won't score in any of them.
I'd be willing to put a wager on that.
He's technically very limited, his awareness isn't great and he wasn't fully fit nor match fit.
Having said that if we had a team that knew how to create chances he'd score goals, probably off the bench, as he has a desire to get in the box.
Don't get me wrong he's nowhere near good enough for a club with aspirations of the top 6 but at the moment we aren't so you have to cut your cloth accordingly.