Having beaten Real Madrid in the semi-finals of the Spanish Supercup, Los Leones went on to defeat Barcelona in the final on Sunday and lift their first piece of silverware since 2015.
It's been a historic last week for them under new manager Marcelino, who is only three games into his tenure. He will be hoping to continue with the same momentum in another cup game on Wednesday.
Ibiza may ply their trade in the third division of Spanish football, but they have proven to be no pushovers in the competition.
They've reached this far by thrashing La Liga side Celta Vigo 5-2 at home, while last year, Barcelona needed a stoppage-time winner to beat them.
On the league front, the Skyblues have impressed this season. They have won eight out of 10 games, drawing the other two. They are the only unbeaten side in their group at this stage.
Ibiza vs Athletic Bilbao Head-To-Head
This will be the first official meeting between these sides.
Ibiza Form Guide (all competitions): D-W-W-W-W
Athletic Bilbao Form Guide (all competitions): L-W-L-W-W
Ibiza vs Athletic Bilbao Team News
The home side have all of their players available for the clash as there are no injury concerns or suspensions to deal with.
Defensive midfielder Peru Nolaskoain sustained an ankle injury last month and won't be available for the clash.
However, we expect Marcelino to make wholesale changes to his side from the one which defeated Barcelona at the weekend in order to rest key players.
Injured: Peru Nolaskoain
Ibiza vs Athletic Bilbao Predicted XI
Ibiza (4-4-2): German Parreno; Francisco Grima Aguilera, David Goldar, Ruben Gonzalez, David Morillas; Kike Lopez, Javi Perez, Manu Molina, Javi Lara; Antonio David Alvarez, Sergio Castel.
Athletic Bilbao (4-4-2): Iago Herrerin; Oscar de Marcos, Unai Nunez, Yeray Alvarez, Yuri Berchiche; Inigo Lekue, Mikel Vesga, Unai Lopez, Jon Morcillo; Asier Villalibre, Kenan Kodro.
Ibiza vs Athletic Bilbao Prediction
As mentioned, Ibiza is not an easy place to secure victory, and we expect them to cause Bilbao some troubles.
However, Marcelino's side are flying high right now, and should coast towards another win despite several key players likely to sit out.
Prediction: Ibiza 1-2 Athletic Bilbao