The hosts will enter the clash off the back of a 4-0 defeat at Athletic Bilbao in La Liga on Friday, while Real Sociedad drew 0-0 with Girona in Spain's top flight on Saturday.
Match preview
Mallorca are bidding to win the Copa del Rey for just the second time in history, with their previous success coming in 2002-03, when they recorded a 3-0 victory over Recreativo de Huelva in the final.
The Pirates have made the final on a further two occasions - in 1990-91 and 1997-98 - but they are certainly the underdogs when it comes to the four teams left in this season's competition, with the other semi-final seeing Atletico Madrid and Athletic Bilbao lock horns.
Mallorca have had to win five matches to advance to the semi-finals of this season's Copa del Rey, overcoming Boiro, Valle Egues, Burgos, Tenerife and Girona.
Javier Aguirre's side will enter this game off the back of successive losses to Real Betis and Athletic Bilbao in La Liga, including a 4-0 defeat to the latter on Friday, with the result leaving them down in 15th position in the La Liga table, just four points above the relegation zone.
Mallorca have not actually beaten Real Sociedad since 2012, and they suffered a 1-0 defeat when the two teams locked horns in the league earlier this season.
Real Sociedad, meanwhile, will enter this match off the back of a goalless draw with Girona on Saturday, with the result leaving them in sixth position in the La Liga table.
Imanol Alguacil's side are some 10 points off the top four at this stage, with too many draws (10) from their 23 matches preventing them from sitting higher up the division.
The Basque outfit are chasing success in two cup competitions this season, with the small matter of a Champions League last-16 contest against Paris Saint-Germain just around the corner.
Real Sociedad have also posted five wins in this season's Copa del Rey, overcoming Bunol, Andratx, Malaga, Osasuna and Celta Vigo, conceding just once in the process.
The White and Blues are two-time winners of the Copa del Rey, with their successes coming in 1986-87 and 2019-20, overcoming Atletico Madrid on penalties to secure the trophy for the first time, before beating Basque rivals Athletic 1-0 to triumph last time out.
The second leg of this contest will take place at Anoeta Stadium on February 27, and the winner will then take on either Athletic or Atletico in the final of the competition.
Mallorca Copa del Rey form:
W
W
W
W
W
Mallorca form (all competitions):
D
W
D
W
L
L
Real Sociedad Copa del Rey form:
W
W
W
W
W
Real Sociedad form (all competitions):
L
W
W
W
D
D
Team News
Mallorca will again be without the services of Pablo Maffeo due to a knee injury, but the home side are otherwise in strong shape ahead of the clash on Tuesday night.
Abdon Prats netted a brace against Girona in the last round of the competition, and the forward is expected to be given the nod in the final third of the field.
Vedat Muriqi is still working his way back from a lengthy absence, so it is likely that his recovery will continue off the bench, with Cyle Larin set to operate alongside Prats, while Omar Mascarell is set to start in midfield.
As for Real Sociedad, Sheraldo Becker, Alvaro Odriozola, Kieran Tierney, Alvaro Odriozola, Aihen Munoz and Carlos Fernandez are unavailable for selection due to injury problems.
Takefusa Kubo's Japan side are now out of the Asian Cup, while Hamari Traore's Mali team have been knocked out of the Africa Cup of Nations, but the pair are still major doubts for this game.
Head coach Alguacil will make changes from the side that started against Girona, with Mikel Merino, Ander Barrenetxea and Robin Le Normand set to come into the XI for the first leg of the semi-final.
Mallorca possible starting lineup:
Greif; Gonzalez, Valjent, Raillo, Copete, Costa; A Sanchez, Mascarell, D Rodriguez; Prats, Larin
Real Sociedad possible starting lineup:
Remiro; Aramburu, Zubeldia, Le Normand, Galan; Mendez, Zubimendi, Merino; Oyarzabal, A Silva, Barrenetxea
We say: Mallorca 1-2 Real Sociedad
Mallorca have been impressive in this season's competition, and we are expecting Tuesday's affair to be close. Real Sociedad are still missing a number of important players, but we are backing the Basque side to secure a narrow advantage ahead of the second leg at the end of the month.