Wolves striker Raul Jimenez has been taken to hospital after he was given oxygen and carried off the pitch on a stretcher during their trip to Arsenal on Sunday.
Jimenez appeared to be knocked unconscious less than five minutes into the game following a clash of heads with David Luiz.
Play was stopped for a total of 10 minutes as both Jimenez and Luiz received immediate medical attention on the pitch.
The collision took place when Luiz was attacking an Arsenal corner at the near post. Jimenez leapt to head clear the set-piece from Willian but was felled by the impact.
The Wolves players, immediately worried, summoned on the medical team.
Luiz - who was bleeding from his head - was bandaged up and checked by the medics before being allowed to continue.
Whereas there was more concern for Jimenez, motionless on the pitch, inside the six-yard box as the medics swept in to treat him.
Jimenez did not move as he was given oxygen, lifted onto a stretcher and the stretcher was placed onto a trolley, wheeled around the pitch and down the tunnel.
Fabio Silva came on to replace him and the game continued, the atmosphere even more surreal than before.
It is believed Jimenez has been taken to hospital and receive further medical attention.