Sevilla have won their last seven games in all competitions, six of those without conceding, while Barca have won six in a row.
The winners of this tie will go on to face either Athletic Bilbao or Levante in the final.
Barca may be on a good run of form, but they have often made a habit of doing things the hard way – the latest case in point being Sunday’s 3-2 win over Real Betis.
The Catalan giants snatched the victory three minutes from time through a Francisco Trincao goal, keeping their slim La Liga title hopes alive in the process.
That is now six wins in succession in the league for Ronald Koeman’s improving side, but with Atletico Madrid showing no signs of slipping up, Barca may have to focus on the cup competitions.
Extra time was required to overcome Cornella and Granada in two of the previous three rounds of the Copa del Rey, with the other victory coming against Rayo Vallecano.
Sevilla also required the additional 30 minutes to see off Leganes in the last 32, before then easing past Valencia and beating Almeria to set up this semi-final.
Julen Lopetegui’s side boast plenty of pedigree in Spain’s top domestic cup competition, having won it on five previous occasions, including three times in the past 11 years.
That pales into insignificance when compared to record 30-time winners Barcelona’s history in the competition, their most recent success coming in 2018-19.
Past success does not count for a great deal, however, and Sevilla have looked very impressive over the past month, going five games without conceding in all competitions.
Los Nervionense held Barca to a 1-1 draw when the sides last faced off in the league four months ago, with Philippe Coutinho cancelling out Luuk de Jong’s opener in that one.
Sevilla are winless in their last five meetings with the Catalans, though, and they were on the end of a humiliating 6-1 thrashing the last time they faced off in this competition two years ago.