I'm not a huge fan of either lineup decision. The forward one is probably fungible, Frederic for Wagner. I think Frederic looked very slow and not able to keep up with the pace. Wagner was meh. It's probably a wash, just rearrainging the deck chairs. This is what the lack of depth has forced them into, rearrainging deck chairs. They can't score goals when the first line is off the ice. This does nothing to move that needle.
I do not like sitting Grzelyck. He has not been good in this series, having been on the ice for 6 goals against which leads all defenseman. Despite this, in my opinion, the Bruins problem in this series is generating offense, not defending. Grzelyck is more likely to help create a goal. I would sit Forbort or Carlo (who has arguably been worse than Grzelyck) and try to up the ante with possession and transition. The problem is, when they get in these funks, Cassidy leans into defense. It's his MO from day 1, one I do not like.