The Spaniard has missed the team's last six matches with the hamstring problem that he suffered against Manchester United in the Europa League.
However, Pedri has proved his fitness for this match and is set to come back into the midfield alongside Frenkie de Jong and Sergio Busquets.
As a result, Gavi is expected to be moved further forward alongside Robert Lewandowski and Raphinha, as Ousmane Dembele is not yet ready for selection.
Dembele was believed to be working towards a return in this match, but the France international is yet to fully overcome his hamstring problem.
Ronald Araujo was suspended for last weekend's 1-0 victory over Athletic Bilbao, but the Uruguay international will come back into the side for El Clasico.
The only other real talking point comes at left-back, where Alejandro Balde is likely to be given the nod over the experienced Jordi Alba, with Jules Kounde lining up at right-back for Barcelona, who are nine points clear of second-placed Real Madrid at the summit.
Barcelona possible starting lineup: Ter Stegen; Kounde, Araujo, Christensen, Balde; F de Jong, Busquets, Pedri; Raphinha, Lewandowski, Gavi