BRISBANE Lions defender Justin Clarke has been ruled out of football indefinitely due to concussion.
Clarke suffered a head knock at training four weeks ago and scans cleared him of any break or fracture to his neck.
However, the 22-year-old has not returned to training since the incident, and has undergone regular concussion testing.
Lions medical staff have consulted concussion specialists in both Brisbane and Melbourne as Clarke's symptoms persisted.
Testing has not shown any damage to his brain, but Lions football manager Matt Francis said the club would take an ultra-cautious approach.
"Our medical staff and Justin are working through his symptoms on a daily basis and there is no timeframe set for his return," Francis said.
"Justin has been completing a university degree during his time with the club and he has very definite plans for his career post-footy - that will influence any decisions going forward."
Clarke – who has played 56 games as a key defender in his three-year career – is studying engineering, has a pilot license and is academically one of the smartest players in the AFL, scoring 99.95 per cent on his Australian Tertiary Admission Rank entrance score.
Thinking about you Clarkey ya legend. Miss ya around the club mate.— Nick Robertson (@nichrobbo) February 16, 2016