Scientists are developing a pitch-side breathalyser that can show if a footballer or rugby player is suffering from concussion.
So far they have only tested gases in the laboratory, but a trial involving 40 students could pave the way to making such a device available to professional and amateur clubs.
The aim is to detect chemicals in the breath shown to be associated with concussion after a blow, or series of blows, to the head.
The potentially serious condition is often missed and there is no practical objective way of testing for it.
Concern is mounting over the health risk to athletes who suffer head knocks, especially children, with some experts calling for a ban on "headers" in school soccer.
Evidence suggests that repeated blows to the head especially can cause serious damage, resulting in the dementia-like symptoms seen in "punch drunk" boxers.
A controversial psychological concussion test that allows a player to return to the game within a few minutes of being given the "all clear" has been strongly criticised by both players and experts.
Scientists behind the breathalyser research said the Pitch-Side Concussion Assessment test being trialled by the International Rugby Board was potentially putting players at risk.
Speaking at the British Science Festival, Professor Tony Belli, from the University of Birmingham, said: "Some players have said it's easy to fudge that test.
"I'm concerned about the way it's being used. If a player has concussion and you send that player back on the pitch you are potentially putting that player's health at risk."
University colleague Dr Michael Grey pointed out that obvious symptoms of concussion often only show up after a significant delay.
The breathalyser would provide a simple, cheap and robust method of testing for concussion without having to resort to costly and difficult procedures such as magnetic resonance imaging (MRI) scans.
Laboratory experiments have shown that tiny traces of certain chemicals associated with concussion can be detected in the blood, urine, and potentially even breath.
The "panel" of chemicals included the central nervous system metabolite N-acetylaspartate (NAA), and the proteins S100B and GFAP.
In the student trial at the University of Birmingham, the researchers will look for correlations between levels of the molecules in blood and urine and rates of concussion among young athletes.
Prof Belli said the same chemicals can be detected in gases, raising the possibility of a breath test.
"It would be similar to a breathalyser," he told the Science Festival at the University of Birmingham. "You would have a detector attuned to measure these chemicals. It would take about five or 10 minutes.
"It wouldn't be quicker than the current test, but it would be more reliable."
The scientists are also looking at using a technique called Transcranial Magnetic Stimulation to spot signs of concussion.
TMS uses a magnetic field to stimulate electrical activity in the brain which can be translated to muscle movements. Research suggests that in concussed patients this connection is impaired.
The scientists were accompanied by Dawn Astle, daughter of former West Bromwich Albion player Jeff Astle who was famous for his heading ability. Mr Astle died from brain trauma aged 59 after being diagnosed with early-onset Alzheimer's.
A post mortem found that large areas of his brain had been irreversibly destroyed.
Ms Astle said, "Dad was probably the finest header of the ball ever in the game. Ten months after he died we attended the coroner's court and the pathologist described how badly damaged dad's brain was. He said there was considerable trauma, similar to the brain of a boxer.
"We can't prove it, but I would suggest that dad was one of the very few people who as a lead goal scorer in the first division scored more goals with his head than his feet.
"As far as we know he was only knocked out once. But what people have to remember is that it's not just about the 90 minutes playing football on a Saturday. Dad's former team mates said that in training it was relentless. They played to dad's strengths and the ball was hit over for him to head continually."