Montreal has Savard on the RHD and Matheson on the LHD as their vets.
X and Harris need to clear waivers as LHD. Guhle, Hutson, and Struble as LHD do not, but I don't envision Guhle getting sent down to the A. Barron RHD needs to clear waivers. Reinbacher and Mailloux the other RHD prospects do not. Figure with Mailloux since he didn't play much in his draft and draft +1 year will spend another year in the A.
So, it's Savard, Matheson, X, Guhle, Harris, Barron, Struble as the returnees with Hutson, Reinbacher competing for a spot.
I believe Guhle has been the guy to swing to the right side so far.
For Harris/Struble, if they are only going to be 3rd pairing Dmen in the NHL, then they need to be able to do something well, be it defend, PK, physical, transition game, etc.. Especially as LHD which is the easier side to replace on the 3rd pairing.
See who is able to lock down their spot.