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.
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.
Sevilla Copa del Rey form: WWWW
Sevilla form (all competitions): WWWWWW
Barcelona Copa del Rey form: WWW
Barcelona form (all competitions): WWWWWW
Barcelona were dealt a blow on Monday as it was confirmed defender Ronald Araujo will miss the next month with an ankle problem, leaving them seriously short at the back.
Lionel Messi made an instant impact with a goal from the bench against Betis and is almost certain to return to the starting lineup here.
As for Sevilla, they will welcome former Barca midfielder Ivan Rakitic back from a one-match suspension.
Lopetegui has plenty of options in attack and will make full use of his squad during an intense run of fixtures.
Sevilla possible starting lineup:
Bounou; Navas, Kounde, Carlos, Rekik; Jordan, Fernando, Rakitic; Suso, En-Nesyri, Ocampos
Barcelona possible starting lineup:
Ter Stegen; Dest, Mingueza, Lenglet, Alba; Busquets, De Jong, Pedri; Dembele, Griezmann, Messi
We say: Sevilla 1-1 Barcelona
Sevilla have won seven games in a row and Barcelona have won six on the spin, so something has to give at the Estadio Ramon Sanchez Pizjuan on Wednesday evening.
The last two meetings between the sides have finished all square and we are backing this one to finish the same way, setting up a tasty second leg at Camp Nou in early March.