I think they just want to see different combinations and work out those kinks before the playoffs start. It was the same for Krug sitting the game before. If McQuaid comes back, you would have 8 capable NHL d-men. Two are going to be the odd-men out.
Let the bottom six of our D (as in, everyone aside from Z and Boychuk) battle it out for a spot in the playoff roster, the competition factor will make any playoff-worthy D-man shine.
When McQuaid gets back, he needs to be brought back up to speed but he will help make it easier for Z and Boychuk to rest up coming down the stretch here.
Having a team firing on all cylinders and dominating the rest of the season
means nothing if your top D-men have either have nothing left in the tank (Z) or are playing through chronic injuries that could heal with some rest (JB55) when the postseason comes around and things matter most???
I want Z and JB to get as much rest as possible. If Bart/Miller/Dougie can't handle big-time minutes to help make that (rest for the top dogs) happen then at least we know where they stand as of now.
But Bart has already proven he can handle over 20 min/game... and i am pretty sure Miller would be fine with an extra 5 minutes a game as he continues his growth as a nice steal for Chia. Mez is a veteran who can handle the minutes, at least once he's physically back to speed.
Dougie will either sink or swim with the bigger minutes, but i say give him that chance... since he could very well be one of the "odd-men out" you mentioned (not necessarily because he should be, but because of Clode). I have a bad feeling Dougie will not be in the regular rotation for playoffs, we might see him in a series or two depending on match-ups... just a hunch.
We already know what we have in McQuaid. He can handle a few extra minutes while Z/JB rest up down the stretch, at least once he's back up to speed. I might be wrong on that one, depending on when he gets back.
I am confident that Miller could play the kind of minutes Bart is playing right now (and has been for a while). It's hard to see either of those two being left off the playoff roster. People might say Bart, but i don't see it happening... Clode clearly is satisfied with Bart's play, as he's been getting fed more minutes than any of the other youngsters on the blue line.
And it can't be Krug, we need him on the PP way too much. Well whatever... time will tell. Krug would be the logical choice to sit if he wasn't such an offensive-minded wizard on the PP. Hell, the kid could very well break Ray B's record by [regular] season's end.
Time will tell.