If Salvador isn't playing the PK, it's pointless to have him in the roster.
Salvador isn't the best defensemen, but in the right, sheltered role, he can be effective. The problem is he lost his partner, Volchenkov, on the PK and Greene lost his, Fayne, as well. The chemistry between those two on the PK was vital. You can't just stick Greene with Salvador and hope it works, cause it clearly hasn't. Also, they are putting Greene on his off side which is a completely different situation that he is used to. They should stick with Salvador-Merrill, Greene-Severson/Larsson and let them get acclimated to each other.
That being said, Salvador needs to play PK and limited even strength minutes unless we are protecting the lead. If we can do that, Salvador's problems will be a lot less noticeable. Whether or not DeBoer does that, that's a completely different story.