Mexico centre-back Diego Reyes will miss the World Cup after failing to recover from a hamstring injury.
The Porto defender has been replaced by midfielder Erick Gutierrez, who plays for Mexican side Pachuca.
A statement from the Mexican Football Federation said: “Diego Reyes wasn’t able to satisfactorily complete his recovery.
“The relevant process will be carried out before FIFA to register Erick Gutierrez in his place.”
Mexico begin their World Cup campaign against reigning champions Germany on Sunday.