The second leg takes place in Spain, with the score standing at 1-1 after the first leg—which took place over five months ago, pre-lockdown.
Both teams have had ample opportunity to prepare, then, and a place in the last eight is at stake, where the winner will face Bayern Munich in all likelihood, with the rest of the competition being played out in Lisbon, Portugal.
Neither side achieved their domestic aims this season, Barcelona ending as LaLiga runners-up and Napoli only seventh in Serie A.
Here’s all you need to know about the game.
When is it and what time is kick-off?
The match will begin at 8pm BST on Saturday 8 August at the Camp Nou.
How can I watch it online and on TV?
The game will be broadcast live on BT Sport 2 and BT Sport Extra 2.
Subscribers can also stream the match on the BT Sport website and app.
Barcelona XI: Ter Stegen, Semedo, Pique, Lenglet, Alba, Roberto, De Jong, Rakitic, Messi, Suarez, Griezmann
Napoli XI: Ospina, Di Lorenzo, Manolas, Koulibaly, Rui, Fabian, Demme, Zielinski, Callejon, Mertens, Insigne
Barcelona — 4/6
Draw — 13/4
Napoli — 9/2