Real Madrid goalkeeper Iker Casillas abandoned Wednesday's match at Valencia with an apparent hand injury.
Casillas was kicked in the left hand by teammate Alvaro Arbeloa while clearing a loose ball in the area in the 13th minute of the Copa del Rey match.
After being looked at by team doctors, Casillas was seen shaking his head before walking off the pitch.
The Spain international was replaced by Adan Garrido.
Madrid leads the quarterfinal 2-0 after the first leg.