The two teams locked horns in La Liga on Saturday, and the points were shared in a 2-2 draw, with Betis fighting back from two goals behind to secure a share of the spoils in San Sebastian.
Betis were on the verge of suffering their 10th league defeat of the season against Sociedad on Saturday, but Sergio Canales and Joaquin both scored in the final five minutes of the contest to secure a point in a 2-2 draw.
Betis will enter Tuesday's match in impressive form, winning four of their last five matches in all competitions, while they have comfortably dispatched UCAM Murcia, Multivera and Sporting Gijon to reach this stage of the Copa del Rey for the first time since 2015-16.
The Green and Whites have won this competition on two occasions, the last of which was in 2005, when they overcame Osasuna in the final.
The Seville outfit have not made the last eight since 2013-14, though, and are likely to face a tough examination by a talented Sociedad outfit on Tuesday night.
Sociedad, meanwhile, have also won the Copa del Rey on two occasions, most recently in 1987, when they overcame Atletico Madrid in the final.
The Basque outfit were due to face Athletic Bilbao in the final of last year's competition, but the match was postponed due to the coronavirus outbreak, and it is now due to take place at the start of April.
The White and Blues have actually won their last eight matches in the Copa del Rey, including a 2-0 success over Cordoba on January 20 courtesy of a double from Willian Jose.
La Real's La Liga form since the end of November has been disappointing, though, winning just one of their last 10 matches, which has seen them drop into sixth position in the table.
Sociedad are also due to take on Manchester United in the Europa League next month, while they will end the month of January with a trip to Villarreal in the league next weekend.
Real Betis Copa del Rey form: WWLWWW
Real Betis form (all competitions): DWWWWD
Real Sociedad Copa del Rey form: WWWWWW
Real Sociedad form (all competitions): WDLLWD
Modibo Sagnan could also feature in the middle of the defence, but Willian Jose has now left the club to join Wolverhampton Wanderers, meaning that Alexander Isak should get the nod through the middle.
Real Betis possible starting lineup:
Joel; Emerson, Sidnei, Ruiz, Moreno; Carvalho, Canales; Lainez, Rodri, Juanmi; Sanabria
Real Sociedad possible starting lineup:
Remiro; Zaldua, Elustondo, Sagnan, Munoz; Lopez, Zubimendi, Illarramendi; Merquelanz, Isak, Barrenetxea
We say: Real Betis 2-2 Real Sociedad (Sociedad on penalties)
This has all of the makings of a classic cup match, and we are predicting goals in Seville. There is every chance that this game could go the distance, and we have picked penalties to separate the two teams, with Sociedad ultimately coming out on top in the shootout.