The hosts are currently in La Liga 2 and aiming for promotion, whilst Bilbao are enjoying a marvellous unbeaten streak since the early stages of December.
Match preview
Eibar's winless run in La Liga 2 extended to four matches during the final game of the competition ahead of the two-week winter break, with Sunday's hosts drawing at home to Sporting Gijon on December 20.
A 22nd-minute strike from striker Victor Campuzano put Gijon ahead at Estadio Municipal de Ipurua however Eibar were not going to settle for a loss easily, with Ager Aketxe netting from the penalty spot in the second period to secure a share of the spoils.
Joseba Etxeberria's men currently sit seventh in the La Liga 2 standings after collecting a respectable 32 points from their opening 21 matches, meaning they are just the point behind sixth-placed Racing Santander and five behind Racing Club de Ferrol in second.
Three players are leading Eibar's Golden Boot race so far in the 2023-24 league campaign, with Jon Bautista, Stoichkov and the aforementioned Aketxe having all made the net ripple on seven occasions.
Athletic Bilbao extended their unbeaten run to a marvellous 11 matches on Thursday night, beating Sevilla 2-0 as La Liga returned following the winter break.
Goals either side of the half-time whistle did the trick for Bilbao at Estadio Ramon Sanchez Pizjuan, with Mikel Vesga finding the net before Aitor Paredes doubled the visitors' advantage in the second period.
Ernesto Valverde's men are in the midst of a real battle for Champions League qualification, with Athletic sitting fourth in the La Liga standings, ahead of Atletico Madrid on goal difference after 19 matches.
Inaki Williams and Gorka Guruzeta have led the way for Bilbao in terms of goalscoring so far this campaign, with both attackers scoring eight times in the Spanish top flight.
Eibar Copa del Rey form:
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Eibar form (all competitions):
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Athletic Bilbao Copa del Rey form:
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Athletic Bilbao form (all competitions):
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Team News
Eibar are expected to be without the services of Roberto Correa on Sunday evening, with the right-back suffering a muscle injury back in November.
The hosts' options in defence are limited further by the absence of first-choice centre-back Frederico Venancio, who is struggling with physical discomfort.
Dani Garcia will be unable to play for Athletic Bilbao against his former employers due to a muscle strain sustained at the end of November.
Valverde could make changes from the side who won at Sevilla on Thursday night, meaning the likes of former Manchester United man Ander Herrera could start.
Eibar possible starting lineup:
Zidane; Tejero, Berrocal, Arbilla, Gutierrez; Alvarez, Pereira, Aketxe, Soriano, Stoichkov; Bautista
Athletic Bilbao possible starting lineup:
Simon; Lekue, Vivian, Paredes, Berchiche; De Galarreta, Vesga, N Williams, Sancet, Berenguer; Guruzeta