Scans on Tuesday confirmed Treloar has tendon damage to his left hamstring, while also straining his right hamstring in the process.
The midfielder will need to undergo surgery in order to repair the tendon injury.
“Adam stumbled, his left leg locked and before he tumbled to the ground his left leg stretched beyond its limit. It seems that he strained his right leg on the way down as he tried to compensate for the force pushing his through his left,” Collingwood’s General Manager of Football Geoff Walsh told collingwoodfc.com.au.
“It is certainly highly unusual, to injure both hamstrings at once. No-one can recall it happening before in football.
“Still, Adam is a fantastic professional and we have no doubt that he will commit himself to the most thorough recovery possible.
“As to what the immediate future holds, we’ll know more after the surgery and his rehabilitation begins.”
Treloar has only missed one game from a possible 57 since making the switch from GWS to Collingwood at the end of the 2015 season.