There’s also a talent gap between Trouba and Lindgren despite them now being paired together as the problem children. If Lindgren is given extended time away from Fox that is going to become obvious even to his strongest supporters, though I'm sure he's going to get to lean on the injury excuse for a while.
I'm not trying to paint Trouba as good either, but I know Trouba can handle bottom pair minutes (not good given his contract, but it is what it is at this point), I don't think Lindgren can handle any thing with out Fox - and he couldn't even paired with Fox last year.
But yeah, Scanlin is bad. My preference would have been to move Lindgren and replace him with a player not in the organization but for what ever reason the FO was hell bent on addressing Trouba first. Lindgren was the easier and more urgent move.