The proposed idea of trading one defenseman, who has had success in the top-four so far this season, for a "legitimate" top-four defenseman does not make much sense for the simple reason that it takes away from the depth of the blueline. In addition, the left side of the Leafs' blueline is aging significantly behind Morgan Rielly, with
T.J. Brodie about to turn 34 and Mark Giordano already 40 and both being UFAs at the end of the season. The left side of the blueline needs as much help as the right side currently and trading away a 25-year-old under team control would hurt the Leafs more than trading for a "legitimate" top-four defenseman that will very likely walk at the end of the season.