Barcelona's creative midfielder, Andres Iniesta, has been ruled out for three weeks, and will miss the Catalan's next four matches after straining his right calf on Saturday.
The 30-year-old started the Classico match in the 3-1defeat at Real Madrid on Saturday, but was withdrawn in the 72nd minute after straining his calf.
Barca have not yet officially revealed the extent of the injury, a medical test carried out on Sunday suggested his condition will require a recovery period of approximately three weeks.