The Partenopei lost 1-0 at Estadio do Dragao last week and will hope that home advantage can help to turn the tie around
The Serie A outfit come into this clash 1-0 down in the tie after Jackson Martinez scored the only goal in the opening leg in Portugal last week.
Napoli had been on a run of eight games unbeaten in the build-up to that encounter, but returned to winning ways domestically on Sunday with a 1-0 victory at Torino.
Porto, meanwhile, are adjusting to life under interim head coach Luis Castro, who tasted defeat for the first time at the weekend with the side's fifth league loss of the season at Sporting Lisbon.
Juan Camilo Zuniga (knee) and Rafael Cabral (knee) remain sidelined for Napoli, while Christian Maggio was reportedly hospitalised with a collapsed lung shortly after returning from the first leg.
Goalkeeper Helton (Achilles) is missing for Porto, while Alex Sandro serves a suspension having surpassed the yellow card limit.