Osasuna will bring a 1-0 advantage into this contest, as a second-half Abde Ezzalzouli effort separated the two teams in the first leg of their last-four tie at the start of March.
Match preview
Athletic are the second-most successful side in the history of the Copa del Rey, having won the competition on 23 occasions, while they have also been runners-up a further 16 times.
The Basque outfit's last success in the tournament came back in 1984, but they made the 2009, 2012, 2015, 2020 and 2021 finals; the winner of this semi-final will take on either Barcelona or Real Madrid for the trophy, with the Catalan outfit 1-0 ahead in their last-four contest.
Athletic will enter this match off the back of a goalless draw with Getafe on Saturday, with the result leaving them in seventh position in the La Liga table on 27 points.
At the time of writing, Ernesto Valverde's side are four points behind sixth-placed Villarreal, so they are in the mix for a European position, while winning the Copa del Rey would see them automatically qualify for the 2023-24 Europa League.
The Lions have work to do following their 1-0 loss in the first leg, and they played out a goalless draw with Osasuna when the two sides locked horns at San Mames in the league back in January.
A terrific goal from on-loan Barcelona attacker Ezzalzouli was the difference in the first leg, with the 21-year-old picking out the far corner of the net after breaking into the Athletic box.
Osasuna have never won the Copa del Rey, but they have previous when it comes to reaching the final, having been present at that stage in 2005, ultimately losing 2-1 to Real Betis.
Jagoba Arrasate's side were also involved in a goalless draw in the league last time out, sharing the points with Mallorca on Friday, with the result leaving them in ninth position in the table.
There are actually only two points between Athletic and Osasuna in Spain's top flight this season, and there was not much to choose between them in the first leg last month.
Osasuna's last victory at San Mames came in the league during the 2019-20 campaign, and they have been involved in three close matches in the last three rounds of the Copa del Rey, beating Gimnastic Tarragona and Sevilla after extra-time, in addition to overcoming Real Betis on penalties.
Athletic Bilbao Copa del Rey form:
W
W
W
W
L
Athletic Bilbao form (all competitions):
L
L
D
L
W
D
Osasuna Copa del Rey form:
W
W
W
W
W
Osasuna form (all competitions):
W
W
D
L
L
D
Team News
Athletic will again be without the services of three players through injury on Tuesday, with Inigo Lekue, Jon Morcillo and Ander Herrera all on the sidelines.
Valverde shuffled his pack in the league last time out, but there will be recalls for Nico Williams, Mikel Vesga, Oihan Sancet and Inigo Martinez in this match.
Iker Muniain should keep his position in the XI, while Inaki Williams could start through the middle, with Gorka Guruzeta and Alex Berenguer potentially dropping down to the bench.
As for Osasuna, Darko Brasanac is available again after serving a suspension in the league last time out, but Ezequiel Avila and Ruben Pena remain on the sidelines through injury.
David Garcia will be back in the middle of the away team's defence after being rested against Mallorca, while there will also be recalls for Moi Gomez, Ezzalzouli and Jon Moncayola.
Arrasate has a big decision to make when it comes to the spot on the right of his front three, and Ruben Garcia could just about get the nod in that area of the field.
Athletic Bilbao possible starting lineup:
Agirrezabala; De Marcos, Vivian, I Martinez, Yuri; D Garcia, Vesga; N Williams, Sancet, Muniain; I Williams
Osasuna possible starting lineup:
Herrera; Moncayola, Aridane, D Garcia, Cruz; Torro, M Gomez, Oroz; R Garcia, Budimir, Ezzalzouli
We say: Athletic Bilbao 1-1 Osasuna (Osasuna win 2-1)
Athletic's rich history in the Copa del Rey has to be taken into account here, but the Basque outfit could face frustration on Tuesday night. Osasuna can be a very tough nut to crack, and we are backing the visitors to secure a draw on the evening, which would send them into the final of the competition.