Porto travel to Spain with a 1-0 lead from last Thursday's first-leg clash, in which French defender Eliaquim Mangala scored a first-half goal before Fernando's late dismissal set up a nervy finish for the hosts.
Sevilla have home advantage in the second leg, though, and will feel confident after thrashing Espanyol 4-1 on Sunday.
Coach Emery saw his side overturn a two-goal deficit in their last-16 clash with rivals Real Betis and has faith they can do similarly against the Primeira Liga champions.
"We've won at home (against Espanyol) and that gives us confidence," Emery said.
"The team is ready, with hope and ability, to deal with Porto. There are 90 minutes of work to come but we can do it with the support of the fans.
"Porto is Porto and they have shown on their pitch they are a very good team. We need more ways to win and we know our opponent will cause us trouble but it's a wonderful challenge."
Porto won the Europa League in the 2010-11 season but are set to lose their Primeira Liga title.
They sit third in the table, 12 points behind leaders Benfica with just four matches to play.
