There's Armia, there's Heinemen, who I think will spend the whole year in the NHL simply because of his contract situation (NHL or Europe only until December 1st). Assuming both return & nobody else is injured, we have two people too many on the roster.
Pezzetta & Slaf seem like the obvious candidates to go to Laval. Once they're there, nothing's stopping the team from calling up Harvey-Pinard over those two. In fact, I think it would be better for everyone if that was the case.