Porto have been in poor form of late having won only one of their last eight matches in all competitions. That said, they are unbeaten in four following their dramatic 1-1 draw with Sporting CP last week.
Following Sunday's 1-0 win at Venezia, Roma have won three of their last five outings. However, victory in Venice was one of just two victories on the road this season, though both away wins came in their last three games on their travels.
With Porto struggling as they acclimatise to Martin Anselmi's three-man backline demands, Roma may just sneak a first leg advantage on Thursday.