Maurizio Sarri believes the absence of Napoli's fans due to security concerns will add to his team's challenge away to Club Brugge on Thursday.
Belgium's capital Brussels is at the highest possible terror alert level, with the government warning of a "serious and imminent" threat of an attack.
That prompted the mayor of Brugge to block all supporters from entering the stadium for the Europa League clash.
And Sarri believes that decision will make the contest tougher for Napoli, even though they have already qualified for the next phase.
"Tomorrow we have a very difficult match psychologically because our fans won't be there and the team have already qualified," Sarri said.
"It will be a good test of our mindset and we will have to show a lot of character to keep our good run of results going.
"Doing well tomorrow [Thursday] against Brugge will help us for our upcoming matches as well.
"That is why I expect a good performance as well as the result. Those are the two things I want out of tomorrow's match."
Napoli, second in Serie A, are on an impressive unbeaten run of 16 matches in all competitions stretching back to August. They will be keen to retain that record ahead of a crunch meeting with first-placed Inter in the league on Monday.
