The former Dortmund and Real Madrid wing-back came off the bench against Cagliari at the weekend, only to be forced off again with injury.
Antonio Conte and his backroom staff will assess the Moroccan right up until kick off to see if he can take part against the Partenopei, but it is likely that Matteo Darmian will play at right wingback.
Arturo Vidal is expected to be missing from the starting XI, but could be available from the bench of Conte wants to add some grit into the centre of his midfield for what is sure to be a battle on Wednesday.
His absence will likely mean a start for Roberto Gagliardini in midfield alongside Marcelo Brozovic, with Nicolo Barella playing slightly further forward behind the two strikers.
Alexis Sanchez started the game against Cagliari but will not play from the start, or potentially at all, versus Napoli, which will mean a return to the starting XI for Lautaro Martinez who'll partner star centre-forward Romelu Lukaku.
Ivan Perisic started on the left at the weekend but didn't impress too much, which could mean a recall for Ashley Young who came on as a substitute.
After an opening start to the season fractured by injuries and positive coronavirus results, it seems that Conte has finally settled on a preferred back three.
Stefan de Vrij, Milan Skriniar, and Alessandro Bastoni will probably start this one, as they did versus Cagliari.