Having dispatched the lowly Terrassa and Yeclano with a combined score of 8-3 in the previous rounds, the Bats are in good form in the competition.
That's in stark contrast to their run in La Liga, which has yielded only four wins from 18 games, as Javi Garcia's side languish 14th in the standings.
However, they will be glad to know that Alcorcon are currently mired in troubles of their own.
The Potters are currently 20th in the Segunda Division and facing a long relegation scramble ahead of them.
In the cup so far, they narrowly beat Lealtad and Real Zaragoza in the previous rounds, winning 2-1 on both occasions.
They have caused quite a few surprises in the competition in the past and are now looking to reach the last-16 for the first time since the 2016-17 season.
Alcorcon vs Valencia Head-To-Head
This will be the first official meeting between the sides.
Alcorcon Form Guide (all competitions): D-W-W-L-W
Valencia Form Guide (all competitions): L-L-D-W-W
Alcorcon vs Valencia Team News
The home side have all of their players available as there are no injury concerns going into the match and no suspensions to deal with either.
The 2019 winners won't have goalkeeper Jasper Cillessen and striker Kevin Gamiero available for selection due to injuries.
However, centre-back Guillem Molina, who was sent off in the first round, is available again after serving his one-game ban.
Injured: Jasper Cillessen and Kevin Gamiero
Alcorcon vs Valencia Predicted XI
Alcorcon (4-1-4-1): Samuel Casado; Javi Castro, Fidel Escobar, Jose Leon, Carlos Bellvis; Juanma Bravo; Ernesto Gomez, Reko, Hugo Fraile, Alvaro Juan; Marc Gual.
Valencia (4-4-2): Juame Domenech; Thierry Correira, Mouctar Diakhaby, Hugo Guillamon, Jose Gaya; Daniel Wass, Carlos Soler, Uros Racic, Denis Cheryshev; Lee Kang-in, Maxi Gomez.
Alcorcon vs Valencia Prediction
Alcorcon are going to make it difficult for Valencia at home, but the visitors have a much stronger squad. The visitors can count on the talent of Carlos Soler, who is having the best season of his career. It should be another high-scoring victory for the La Liga outfit.
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Prediction: Alcorcon 1-4 Valencia