Ernesto Valverde explained Sergio Busquets was a late omission from Barcelona's Clasico line-up against Real Madrid due to a fever.
The Spain international was originally named among Barca's starting XI but was a late withdrawal with Ivan Rakitic taking his place in Wednesday's 0-0 draw.
Neither side was able to make inroads over the 90 minutes, which were marked by pro-Catalan independence protests inside Camp Nou and violent clashes outside.
Editors' Picks
Confusion reigned with some reports suggesting Busquets was going to be among the substitutes instead, but head coach Valverde confirmed it was illness that meant he missed the goalless draw at Camp Nou.