This is what KN said when he signed:

“But there’s certainly no rush. This is something of a medium – long-term project.

“We’re not looking for him to be brilliant by January – he’s a player for the future of the club. He needs time and patience – we’re not putting him under any pressure to produce immediately.

So it's no big deal that he's taking some time to be ready. I would be more concerned that there's no obvious plan for how to gel the other new signings into the team.