A complete mismatch on paper, Los Che look far the better side coming into this tie. However, this is not an ordinary campaign by Valencia's standards and this tie could very well be another stumbling block for the La Liga outfit.
Javi Gracia's first season in charge of Valencia has been anything but smooth sailing, with problems on and off the field often negatively impacting performances.
Following their much-needed league win against Real Valladolid last time out, the team currently sit 14th in La Liga, with just three points separating them from the drop zone.
Fortunately for Gracia's men, their Copa del Rey outings have been a largely positive experience so far, with both fixtures ending in resounding scorelines for Los Che.
For Alcorcon, their encouraging results in the cup come as a breath of fresh air for boss Juan Antonio Anquela.
Los Alfareros are in the midst of a torrid campaign in Spain's second-tier, with just one win in their last six games. Anquela will no doubt hope that a shock win against Los Che will help inspire his side in the league.
In the second round of the cup, Anquela's side bested fellow Segunda Division strugglers Real Zaragoza. The home side left it late but eventually came back from a goal down to win the tie 2-1.
Much to the surprise of the home fans, the winner in that game came from the centre-back Jose Leon Bernal. Anquela will not care who finds the back of the net against Valencia this Sunday, just so long as they do.
Alcorcon Copa del Rey form: WW
Alcorcon form (all competitions): DDWWLW
Valencia Copa del Rey form: WW
Valencia form (all competitions): DLLDWW
Alquesa will no doubt make changes this weekend in terms of team selection. Considering his side's league position, it may be considered wise to rest some of his key starters.
One player that is not likely to take any part is Hugo Fraile, who is currently out with a muscle injury.
Against Yeclano, Gracia did make changes to his starting XI but also included a number of his best-attacking players such as Goncalo Guedes and Lee.
Alcorcon possible starting lineup:
Casado; Castro, Escobar, Leon, Bellvis; Gomez, Reko, Bravo, Boateng, Juan; Llamas
Valencia possible starting lineup:
Sabater; Correia, Sibille, Mangala, Lato; Musah, Racic, Koindredi, Guedes; Vallejo, Sobrino
We say: Alcorcon 0-3 Valencia
It will take a lot for Alcorcon to progress to the next round against a Valencia side that, on paper, is brimming with talent and natural ability. Los Che have been looking pretty good in the cup so far and we think they will keep their run going on Sunday with a big win.