The Dutch midfielder has a hamstring strain and won't play against Rayo on Wednesday
Frenkie de Jong has joined Pedri on the sidelines for Barcelona's trip to Rayo Vallecano on Wednesday, with Ousmane Dembele, Martin Braithwaite and Ronald Araujo also missing.
The Dutch midfielder got injured in the Clasico, leaving Ronald Koeman with just Sergio Busquets of his first-choice midfield three. Gavi, Riqui Puig, Sergi Roberto and Nico Gonzalez are the other options.
Dembele is not yet fit to return to action despite returning to training, while Ansu Fati is a doubt despite being named in the travelling squad.
Koeman says that Ansu has a minor problem carried over from the Clasico, but stressed it is unrelated to the injury he's just returned from following a 10 month layoff.
Barça squad vs. Rayo Vallecano: Ter Stegen, Neto, Iñaki Peña, Dest, Piqué, Busquets, Riqui Puig, Memphis, Ansu Fati, Demir, Coutinho, Lenglet, Luuk de Jong, Jordi Alba, Agüero, Sergi Roberto, Mingueza, Umtiti, Eric Garcia, Balde, Nico, Gavi.