That was genius.
While I understand Derek's frustration here, the reason why Stone and Nilsson sat wasn't directly related to being skated hard. Since I imagine they were only cleared by Medical that day -- it wouldn't have been a story on Saturday if they'd skated Friday as well -- they probably hadn't done much hard skating or seen much contact since their respective injuries, and certainly hadn't played at anything like game speed. Even if they kept up with their regular workouts at the gym, they would still need at least a couple of practices before they had their "game legs": that is, they'd need that amount of time to get their muscle coordination and timing back, for both their skating and their game skills. Otherwise, they'd basically look like everyone does in the early preseason: a gear slow and a half-second off on just about everything. Even given the current state of the team, I can't imagine having them playing at a suboptimal pace right after coming back from an injury, especially with five days of rest and practice ahead, would have been a wise move, for either the players or the team.