Both Gavi and Tomas Conechny were forced off after a clash of heads.
After Barca's 1-0 win, the club announced: "During this afternoon's match against Alavés, Gavi suffered a head injury without losing consciousness. The tests were normal and he has been discharged home."
TV cameras picked up the conversations between staff and Gavi as he attempted to pick himself up after the incident.
After asking Gavi several questions, which were captured by the Movistar cameras, it was clear that the Barça number 6 was not fit to continue on the pitch.
The one that was decisive was: "What day is today? "
Gavi's response alerted medical chief Ricard Pruna and those surrounding him: "I have no f***ing idea".
He asked him another question: "And what time is it? Can you tell me the time of the match?"
He was more precise there. "Two o'clock," he said without hesitation.
But the doctor didn't like the first answer and that was when he said they had to leave the field. The player resisted a bit while Raphinha, as captain, told him to do as he wsa told: "Listen to me, you've suffered a blow to the head, brother."
Coach Hansi Flick came on the scene, telling Pruna that he had the last word.
"It's a shock," the doctor told him in English.
Faced with this statement, the German went to speak to Gavi to convince him that he could not continue: "We have to be careful".