Phaneuf is a LD and has only been playing that side under Carlyle. Wilson was using him on his weak side as a RD.
Right now we've had:
Phaneuf-Holzer
Gunnar-Kostka
Fraser-Franson
Gardiner has to take a spot from either Phaneuf, Gunnar or Fraser from what we've seen. That's not to say Carlyle won't change his philosophy in the future but he hasn't given any indication up to this point that he will.
Wouldn't it make some sense to have Gardiner playing on the right side with the Marlies if it's going to be such a challenge to crack the the line up on the left side?