I'm in the camp that says that if he dresses Chabot, Boucher might go with 7/11 and Varone will sit unless someone else is hurt.
I don't think any of the forwards really deserve to be taken out at this time so when he dresses Chabot my preference would be that he sits Boro or Wideman. Chabot should take a normal 3rd pair rotation and if he can't cut it then finish the game with 5 D and sit him again or send him back. They can control Chabot's minutes and playing situations as much as possible but they shouldn't have to baby a NHL pro D. Save the gimmicks for a time when a top 4 D has a small nagging injury but the coach wants to dress him anyway to see if he can get some important minutes from him.
Agreed about Varone being the most likely to sit, but I think he's out for Puempel. Neil playing few mins can still throw that one big hit. Guys like Varone need some mins in offensive situations to provide value.
If we bring in both Puempel and Chabot, I'd guess that Varone sits for sure. Not sure about who else though, would have said Wideman before last game, but he was much better against the Habs. Boro was exactly what you want from him that game too, physical, but otherwise not too noticeable (good or bad).
Touch choice for the coach if he wants to sub both in right now imo.