If Colin White was getting games for Ottawa I'd be more inclined to say yes to Sheary for Pageau because then there would at least be a succession plan in place. However if Pageau's out, I'm not really sure who fills that #3C role in Ottawa, or who scores for the Sens against Montreal. Maybe Zack Smith because he wouldn't be needed in a top 6 winger role if Sheary was in the lineup.
I know he's injured but if Chris Wideman was included as well, what about Wideman and Pageau for Sheary and Sheahan?
Is Wideman any better than Ruhwedel? And if so, is it enough to move Sheahan? Sheahan has been very good for PIT... I'd just move him to 4C and carry on. Qualify him this summer (~2.2m) and deal with him then if we do not want/need him.