Duchene, who was scratched for the opener against Norway and then Wednesday night's quarter-final against Latvia, is expected to step into Tavares' spot on the fourth line when Canada plays the United States on Friday for a spot in the gold-medal game.
Tavares suffered a left-leg injury in Canada's 2-1 win over Latvia and coach Mike Babcock said the New York Islanders star is out for the rest of the tournament.
That's a major loss for Canada, even though Tavares did not record a point in three-plus games.
It will be up to Duchene to provide the same stability in the middle of the fourth line and perhaps even add a scoring spark to a lineup that needs it. Canada has scored just 13 goals in four games, and only six have come from the forwards.