A device that instantly diagnoses concussion by testing a player's saliva could be available to use by 2022.
Premier League stars are taking part in a study in which the saliva of those with head injuries is tested and compared to that of uninjured players.
The University of Birmingham has established that saliva contains testable biomarkers if a concussion has occurred.
It is hoped club doctors will soon be able to test pitchside using a handheld device.
Professor Tony Belli, who is leading the study, told Sportsmail: 'The concussion assessments done at the moment are very subjective.