The second-placed teams in the Europa League groups play the third-placed teams in the UEFA Champions League groups.
Barcelona, who were knocked out of the Champions League after finishing third in their group, will host Napoli, first leg on February 17, before the return leg away a week later.
Barcelona’s rival, Sevilla, will meet Croatia’s Dinamo Zagreb, while Germany’s Borussia Dortmund will play Scotland’s Rangers after the draw in Nyon, Switzerland, on Monday.
Razen Bale Sport Leipzig will meet Real Sociedad, Zenit St Petersburg will play Real Betis, while Sherif Tiraspol of Moldova will meet Sporting Braga.
Italy’s Atalanta will meet Olympiacos of Greece and Porto will play Lazio.
The winners of the eight matches will join the eight winners of their groups in the Europa League in the round of 16, the drawing of which will be drawn on February 25.