Diego Simeone's side will enter the contest off the back of a 1-0 defeat to Mallorca in La Liga on Wednesday, while Almazan drew 1-1 with Mirandes II in Tercera Federacion Group Eight on Saturday.
Match preview
Almazan, as mentioned, play their league football in Tercera Federacion Group Eight, which is now the fifth tier of Spanish football.
Diego Rojas's side will be looking to pull off one of the biggest shocks in the history of the competition on Saturday evening, as they take on one of the most glamorous clubs in Spanish football.
Almazan will actually bring a five-game unbeaten run into this contest, although four of those matches have finished level, including a 1-1 draw with Mirandes II in the league last weekend.
The team are currently ninth in their domestic table, boasting 10 points from their opening nine matches courtesy of a record of two wins, four draws and three defeats.
Atletico, meanwhile, will enter this match off the back of a 1-0 defeat to Mallorca in La Liga on Wednesday, which made it five games without a victory for the out-of-form side.
Simeone's team have only picked up one point from their last three league matches, which has seen them slide down into sixth position in the table, while they had a disastrous Champions League group-stage campaign, finishing bottom of Group B, failing to even qualify for the Europa League.
The Copa del Rey is already Atletico's only realistic chance of securing major silverware this season, so the competition has certainly taken on added importance.
The Red and Whites have won this tournament on 10 previous occasions, making them the fourth-most successful team in the history of the competition behind Barcelona (31), Athletic Bilbao (23) and Real Madrid (19).
Atletico last lifted the trophy in 2012-13 by beating Real Madrid in the final, and it could provide a welcome distraction due to the team's difficulties in La Liga and European football.
The pressure is seemingly growing on Simeone due to the team's struggles, but the club allegedly still have no desire to replace the Argentine at this moment in time.
Almazan form (all competitions):
Atletico Madrid form (all competitions):
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D
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Team News
Almazan head coach Rojas is expected to play the majority of his important players in this match, with leading goalscorer Edipo Rodriguez set to feature in the final third of the field.
The 29-year-old has four league goals to his name this term and could be joined by Daniel Iraola as part of a front two, while Khalifa and Javier Albitre are likely to feature in midfield.
Victor Moreno, Diego Mateo, Anto and Rafarl Checa have all been important players in the league this season, meanwhile, and they are expected to operate as the back four against Atletico.
The visitors, meanwhile, could have a fully-fit squad for this match, with Joao Felix and Jose Gimenez also available after serving suspensions on Wednesday night.
Head coach Simeone will undoubtedly make changes for this weekend's contest, with Matheus Cunha, Saul Niguez, Sergio Reguilon, Koke, Thomas Lemar and Angel Correa potentially all starting.
Sergio Diez could also be handed a start at right-back, while Carlos Martin might come into the front three, with Simeone potentially changing his entire starting side for this match.
Almazan possible starting lineup:
Gonzalez; Checa, Anto, Mateo, Moreno; Khalifa, D Martinez, Elvira, Albitre; Iraola, Rodriguez
Atletico Madrid possible starting lineup:
Grbic; Diez, Hermoso, Gimenez, Reguilon; Koke, Saul, Lemar; Martin, Cunha, Correa
We say: Almazan 0-4 Atletico Madrid
Atletico have struggled in recent weeks, but it is very, very difficult to imagine a shock result occurring on Saturday. Almazan are likely to be in for a tough 90 minutes against the capital giants, and we are expecting Simeone's side to comfortably progress into the next round of the competition.