Real Madrid defender Alvaro Tejero faces a ban after being sent off for spitting at an opponent at the end of Castilla's bad-tempered 2-2 draw at Amorebieta at the weekend.
Tejero, 20, was set to be called up by coach Zinedine Zidane for Wednesday's Copa del Rey quarterfinal second leg at Celta Vigo with Marcelo, Dani Carvajal, Danilo and Fabio Coentrao all injured.
He is now likely to be unavailable for the game -- in which Madrid must overcome a 2-1 deficit -- after referee Iosu Galech Apezteguia wrote in his report that he had "spat in the face of an opponent" during an altercation following the final whistle at Amorebieta.
"In the 90th minute the player Tejero was sent off for the following reason: Spitting in the face of an opponent after the game had ended, while still on the pitch," the report said.
Tejero featured for Madrid earlier in the Copa del Rey campaign and was called up to train with the squad on Monday.
With none of Zidane's specialist full-backs available, it was thought he would at least be named on the bench.
But that now depends on whether the authorities announce a punishment on Wednesday, when the player could already have been named in the squad for the game in Galicia.