This season, if there is one team that will have to prove that it can win in the playoffs, it is the Toronto Maple Leafs.
In a press scrum, Keefe said, in all seriousness, that he plans to use Marner as a defenseman this season on occasion, which is why he's been practicing with defenseman Morgan Rielly a few times since Maple Leafs camp began.
It may seem strange to some, but older players may remember that Scotty Bowman, back when he was managing the Detroit Red Wings, used center Sergei Fedorov as a defenseman on occasion.
Of course, that's not the norm, but when a player is versatile, he can be used in any capacity. However, Sheldon Keefe's plan seems to be to use Marner in specific situations, not to make him a full-time defenseman. There is a nuance to be made here.
But you can look at it one of two ways, either the Maple Leafs are deficient defensively, or Marner is an ultra versatile player.