Well, this is going to be fun!
Both the Sabres and Bruins are gunning for that sweet, sweet Draft Lottery position, and have largely been deeply inconsistent if not outright awful in-between impressive games. Both have goaltenders on deeply disappointing runs, and a handful of players who are the single biggest drivers of anything going on when it comes to ice-time.
Even better, both teams are riding high on hard-fought wins the day before against eastern conference leaders!
So yes, fatigue will be a concern for both sides, but principally for Boston in the fact that unlike the Sabres, they really are just tied to two skaters entirely.