Wisniewski's cap hit doesn't really matter as we are unlikely going to be a cap crunched team in the near future. The real dollar amount does matter, but that is going down over time.
The one way in which Wisniewski's cap matters is that we can't afford to scratch him. Same goes for Johnson and Tyutin. Those guys, when healthy, are IN for cost and political reasons. They are largely shielded from reprisal for having a poor span of play. I would also put Murray in there due to his draft status and promise.
Savard is not in that group. Why? Because Savard being in has mostly to do with how he is playing. If he is playing well, as he currently is, then he is in. If, however, his play goes to crap, he would be in a similar situation to Prout. He doesn't carry the financial burden or have the expectation of a top pick coming along with him.