Napoli could become the first team in Champions League history to qualify from their group after only three games on Wednesday, providing welcome relief from their recent troubles.
A home win over Besiktas, plus a draw in the other Group B game between Dynamo Kiev and Benfica, would guarantee last season's Serie A runners-up a place in the last 16 for only the second time.
The match will also see Besiktas midfielder Gokhan Inler return to the club where he spent four years of his career. The former Switzerland captain has promised not to celebrate if he scores.
Napoli, unbeaten in their last 18 European matches, have six points from their first two games although their 4-2 home win over Benfica three weeks ago, when they scored four times in less than an hour, now seems a world away.
Maurizio Sarri's side have lost both Serie A games they have played since, dropping to fourth in the table and falling seven points behind leaders Juventus.
They have also lost striker Arkadiusz Milik to a long-term knee injury and do not have an obvious replacement.
Manolo Gabbiadini was given the job against AS Roma on Saturday but the 25-year-old failed to make an impact and was jeered off when he was substituted after 57 minutes in the 3-1 defeat.
Another alternative would be to field Belgian international Dries Mertens as a so-called false number nine, a role he performed when he replaced Gabbiadini on Saturday.
"Dries does these things well, it’s a role he can play but of course we can’t expect him to be a centre-forward in the traditional sense," Sarri said.
Napoli were playing flowing football early in the season but the plaudits have dried up as quickly as the goals for Sarri, who is facing criticism for failing to rotate his squad.
His players laboured on a warm afternoon against Roma, prompting critics to question why he does not give more fringe players a chance.
Midfielders Marko Rog and Amadou Diawara have yet to get on the field since they were signed in the close season while forward Emanuele Giaccherini has played a total of 19 minutes since he was signed from Sunderland.
Nineteen-year-old Diawara's absence is especially surprising as he cost Napoli 14 million euros from Bologna.
Besiktas have drawn their opening two games in the group and are unbeaten in all competitions this season, apart from losing on penalties to Galatasaray in the Turkish Super Cup.
