People have extremely short memories and forget how fantastic Soucy was last season. A total stabilizing force. Whatever mojo he had last season isn't there this year, although there's been some recent games where he's looked close. I really can't seem them trading him away for an upgrade. Moving on from Soucy would necessitate finding another replacement. Ideally you're totally overhauling the third pair so you're running two 2nd pairs like last season.
Soucy was so good last year that he completely changed how the d corps played, which makes his drop off this year even more baffling.
I've no idea wtf is going on with him, but I have noticed that he's been roaming A LOT more than last year and that's probably contributing to his poor play.
He needs to keep his game simple, instead of trying to be Hughes 2.0.
I'd not be surprised if the number of times he's been caught out of position this year which then led to a goal or great scoring chance against has already eclipsed those same metrics from last year.
I think a big part of this is on the coaching staff and the new system they are trying out.