Didak injured his hamstring at training earlier this week, and his absence will stretch an already thin Collingwood forward line.
In better news for the Pies, Heath Shaw has recovered from his hamstring injury and is fit to play after training strongly at Gosch's Paddock on Thursday morning.
Former Lion Anthony Corrie is also a chance to make his Collingwood debut after knocking on the door for the last couple of weeks.
One player who will definitely be missing from the clash is Kangaroos skipper Brent Harvey, who dislocated his elbow in Saturday night's loss to Richmond.
Collingwood coach Michael Malthouse was the coach of the International Rules team that had Harvey as captain, and said while he would be tough to replace, the Roos were in the same boat as many teams.
"He's an outstanding young man, Brent Harvey – I've been very fortunate to have something to do with him at the end of last year,” Malthouse said on Thursday.
"He's not an easy player to replace because he's their club captain and he's in the top echelon of their player group.
"But there wouldn't be a side running around at the moment that hasn't got good players out, and that's what you come to expect in AFL football.
"There's very few sides who've got their best side to pick from.
"They'll pick their best 22 and our best 22 will know that Harvey's not there. But that's insignificant because they'll also know that for our side, Didak's not there."
