The Brazil international moved to Camp Nou at the start of January, but his debut was delayed by injury that kept him inactive for almost three weeks after signing.
Ivan Rakitic, Paulinho and Andres Iniesta accompany the playmaker in the middle of the pitch, with Lionel Messi and Luis Suarez starting up front.
Fellow new face Yerry Mina is included as a substitute, and could also make his Barca and Liga bow.
In total Ernesto Valverde makes five changes from his Copa side, with Marc-Andre ter Stegen returning to duty between the posts.
Nelson Semedo and Lucas Digne come in for Aleix Vidal and Jordi Alba at full back, while Paulinho deputises for Sergio Busquets and Coutinho takes the place of Sergi Roberto.
Barcelona: Ter Stegen; Semedo, Pique, Umtiti, Digne; Rakitic, Paulinho, Iniesta; Coutinho; Messi, Suarez.
Substitutes: Cillessen, Sergio, Paco Alcacer, Jordi Alba, S.Roberto, Aleix Vidal, Yerry Mina.
Alaves: Pacheco; Alexis, Maripan, Laguardia, Duarte; Ibai, Medran, Wakaso, Pedraza; Guidetti, Sobrino.
Substitutes: Sivera, Martin, Vigaray, Pedraza, Munir, Diéguez, Demirovic.