The centre-back hurt his knee against Espanyol on Monday (AEDT) and there were doubts about whether he would even make the matchday squad this week.
Spain international Pique declared himself ready to play on Friday, though, and head coach Ernesto Valverde has decided to risk him in the starting line-up.
It means $A18.5 million signing Yerry Mina must wait for his debut, with the Colombian only included on the bench. Philippe Coutinho is also among the substitutes.
Luis Suarez starts despite the risk of a suspension for the final if he were to receive a yellow card during the clash at Mestalla, where Barca take a 1-0 aggregate lead.
Jasper Cillessen will begin in goal, behind a back four of Jordi Alba, Pique, Samuel Umtiti and Sergi Roberto.
Captain Andres Iniesta, Sergio Busquets, Ivan Rakitic and Andre Gomes are in midfield, with Lionel Messi partnering Suarez in attack.