Richmond rookie list hopeful Travis Casserly will fight to clear his name and avoid a two-year ban after testing positive to a performance-enhancing drug.
The 23-year-old defender, who spent 2006-08 on the Tigers' primary list, is battling for his AFL future after spending the past two seasons playing with WAFL club Swan Districts.
He is one of three players currently training with Richmond who are vying for one remaining Tigers rookie spot, along with Victorian Mitch Keddell and South Australian Liam Corrie.
Casserly's positive test stems from Swan Districts' one-point win over Claremont in last year's WAFL grand final, in which then-teammate Andrew Krakouer won the Simpson Medal as best afield.
The 23-year-old is understood to have tested positive to a a drug similar to pseudoephedrine, which contains stimulant properties.
It is believed to have been contained in a cold and flu tablet Casserly consumed, as he was feeling unwell in the lead-up to the grand final.
An anti-doping violation hearing is expected to be held within the next fortnight, with Swan Districts football operations general manager Phil Smart saying Casserly will protest his innocence of any offence.
"We will be defending it vigorously," Smart said.
A Richmond spokesman said the club would not comment, as Casserley was not currently a listed Tigers player.
But the defender had been set to play for the club in Friday night's match against the Indigenous All Stars in Alice Springs, as was Keddell.
That game was cancelled due to the threat of severe weather.
Casserly is one of two WAFL players to have tested positive to a performance-enhancing drug last season.
East Perth 20-year-old Dean Cadwallader, who had been rated a potential AFL draft prospect, admitted to using banned steroid nandrolone.
Former Richmond and Footscray ruckman Justin Charles is the only AFL-listed player to have been sanctioned for performance-enhancing drug use.
He received a 16-game suspension in 1997 for using the steroid boldenone.