Sevilla lost the first leg in Portugal 1-0 last week but should be confident of overturning that deficit on Thursday as they have won five of their past six games at home in all competitions.
As one of the leading goal-scorers left in the Europa League this season, Gameiro has the pedigree to perform at continental level and showed he was in fine touch in Sevilla's La Liga encounter on Sunday.
Sevilla thrashed Espanyol 4-1 in the league with Gameiro scoring twice.
Gameiro has scored eight goals in Sevilla's past 13 games.
The 26-year-old Frenchman controlled Vitolo's cross on the stroke of half-time on Sunday before volleying into the net, while his second came in the 84th minute with a sharp finish after a one-two with Marko Marin.
The former Paris Saint-Germain striker has four goals in the Europa League proper this season (plus one in the qualifying stages) - level with Valencia's Paco Alcacer as the most prolific goal-scorer whose side has yet to be eliminated.
Red Bull Salzburg striker Jonathan Soriano is on top of the goal-scoring charts with eight.
Porto won the first leg thanks to a diving header from skipper Eliaquim Mangala, who got on the end of Ricardo Quaresma's cross.
But in a blow for the 2011 Europa League champions, they will have to do without Brazilian midfielder Fernando in the second leg, after he was sent off with three minutes to go in Porto.
Porto warmed up for their trip to Spain with a 3-1 victory over Academica in Liga Sagres, the fourth win in five games for Luis Castro's men.
The Portuguese club also won the Europa League's predecessor, the UEFA Cup, in 2003, while Sevilla won that competition twice - in 2006 and 2007.
A draw will be enough for Porto to advance, while their clean sheet in the first leg means they also in the box seat to win on away goals.
