All of Fabio Cardoso, Evanilson, Otavio, Gabriel Veron and Francisco Meixedo occupy spots in the treatment room, while Galeno and Mateus Uribe are also unlikely to make the cut this week.
The Dragons' fitness woes were exacerbated in the weekend's Primeira Liga win over Rio Ave too, as Toni Martinez had to be withdrawn late on after scoring the only goal of the contest in the first half.
It is unclear how severe Martinez's problem is, but Danny Namaso may be required to partner Mehdi Taremi in attack - the Iranian struck five goals and two assists in the group stage to seal Porto's progress as group winners.
The visitors' depleted midfield should be manned by Marko Grujic and Stephen Eustaquio, and a first-ever Champions League appearance could come the way of Andre Franco on the right-hand side.
One Pepe should start on the left for Porto, and the attacker's namesake - 39-year-old defensive veteran Pepe - will likely line up from the first whistle too, partnering David Carmo in front of the in-demand Diogo Costa as Ivan Marcano drops to the bench.
Left-back Wendell has made a miraculous recovery from being stretchered off against Vizela two weeks ago, but Champions League regular Zaidu Sanusi should get the nod here, as Joao Mario occupies the right-back role.
Porto possible starting lineup: Costa; Mario, Pepe, Carmo, Sanusi; Franco, Eustaquio, Grujic, Pepe; Taremi, Namaso