Leeds are being investigated by the FA after Brentford's Sergi Canos appeared to be struck by an object thrown from the crowd at Elland Road on Sunday.
Canos was celebrating scoring the Bees' second goal in front of home fans in the 2-2 draw when a missile, believed to be a bottle, was hurled in his direction.
The Spaniard went down to the ground clutching the back of his neck and Bryan Mbeumo was also seen holding his head.
Irate Brentford players were then seen remonstrating with Leeds supporters in the Don Revie Stand.