The Catalan coach will be hoping to leave on a high with a 14th trophy in his last match as boss, and has selected the youngster at right-back to replace Dani Alves
Montoya begins at the back in place of the injured Dani Alves, while Javier Mascherano partners Gerard Pique in the absence of sidelined skipper Carles Puyol and Jose Pinto starts in goal as he has done all the way through this competition.
In his last game as Barca boss, Pep Guardiola names his classic midfield three of Xavi, Andres Iniesta and Sergio Busquets, while Lionel Messi is flanked by Pedro and Alexis Sanchez in attack.
Meanwhile, Athletic coach Marcelo Bielsa has gone for a 4-3-3 formation and has opted to restore Javi Martinez to the midfield after the Spain star featured in defence for most of the season.
Ibai Gomez and Markel Susaeta start in attack alongside Fernando Llorente for the Basques, but Ander Herrera and Ander Iturraspe are both on the bench.
Athletic Bilbao (4-3-3): Iraizoz; Iraola, Ekiza, Amorebieta, Aurtenetxe; Javi Martinez, De Marcos, Muniain; Susaeta, Llorente, Ibai
Subs: Raul, Toquero, San Jose, Gabilondo, Inigo Perez, Gurpegi, Ander Herrera
Barcelona (4-3-3): Pinto; Montoya, Pique, Mascherano, Adriano; Busquets, Xavi, Iniesta; Pedro, Alexis, Messi
Subs: Valdes, Bartra, Thiago, Keita, Afellay, Cesc, Tello