It's time for Napoli to find a suitable replacement for Lukaku to fill the void in their forward line. I'd even say Napoli shouldn't expect anything from Lukaku this season.
Lukaku has a serious injury that is expected to take three months to heal, and there's no guarantee he'll be able to return to top form after recovering from it. Now is the time for Napoli to race against time before the transfer window closes to find a new striker.
That should be because as far as we see Napoli so seriously fixing the team by bringing in several players but so far they have not taken any approach as one of the options for the change for Lukaku on the front lines. Injury experienced by Lukaku indeed has a great impact on the front lines even though there are substitutes on the team who can take these opportunities to replace Lukaku's role.
But if you look at Napoli's journey this season with their involvement in the Champions League, then a good squad is needed to make the best opportunities for them, especially talking about the steps to maintain Scudetto in Serie A which is much more difficult because there are many competitors that might be faced if they do not have a better squad for Napoli.