Villarreal defender Ruben Semedo faces accusations of assault, kidnap and robbery after being arrested in Valencia on Tuesday.
A spokeswoman for Spain's Guardia Civil told ESPN FC that the arrest had been made after an official complaint by the alleged victim of an incident last week.
Late on Tuesday, Villarreal said they had opened disciplinary proceedings against Semedo.
A club statement said: "Following the events that have been revealed this morning regarding our first team footballer Ruben Semedo, Villarreal wants to express its maximum concern and announces it has opened a disciplinary file on the player to investigate what happened.
"The club will take the necessary disciplinary measures it deems pertinent with maximum rigour and strictness in view of the severity of the events."
Semedo joined Villarreal last summer and has made just four league appearances.
He has been sidelined since undergoing surgery on his thigh in December.