Not writing him off, but there hasn't been much in the way of encouragement from what we've seen of him so far.
what do you expect to see from him in 31 minutes of game time spread over 5 appearances?
that's his entire football for the last four months, and he's hardly getting used to the pace of the Premier League in that amount of time is he?
he needs a pre-season, and I dare say the original plan was to buy him in the summer but we got spooked into acting more quickly, possibly by Lukaku making nods at the exit signs? it'll be more helpful to Niasse in the summer that he knows his team-mates, then it's all about getting up to speed and gaining fitness. Or maybe his agent played a blinder and convinced us someone else was about to sign him?