Remember when the Leafs put Jarnkrok on defense in preseason and he looked decent? You kinda want your bottom 4 defensemen to be barely noticeable out there because it means they're being efficient, not making mistakes. The same logic doesn't really apply to forwards. Jarnkrok is very quiet out there.
In the Leafs endeavor to experiment with 'positionless hockey' I wonder if there's an argument to be made for swapping Jarnkrok (RH) onto RHD, and giving ol' Rasmus Sandin a turn at forward? The basic premise is Sandin plays risky back there but is too far back from the play to generate offense. Jarnkrok has a big shot but is an inert player in the wrong position.