But David Ospina's life is not at risk.
He did regain his consciousness and was taken by an ambulance to hospital where he will be closely monitored for a number of hours. He was replaced by Alex Meret and stretchered off the pitch before being transported to hospital.
Following the treatment, Ospina went on to concede twice before fainting on the pitch without anyone around him in the 44th minute, prompting his anxious Napoli team-mates to call for the stretcher.
After the initial contact, physios came on and bandaged up his head.
Medical staff rushed on to attend to Ospina.
He joined Napoli on a season-long loan deal in August 2018.
Napoli manager, Carlo Ancelotti, further divulged initial scans on the player had indicated the injury was not very serious.
Napoli had taken a two-goal lead thanks to goals from Amin Younes and Jose Callejon but Kevin Lasagna and Seko Fofana hit back to score past Ospina. "They did well to get at us after we went 2-0 up, but then in the second half we collected ourselves and in the end I think we deserved to win based on how we performed".