I don't know, maybe Mac would be happy to be traded if he thinks he could get a chance at starting on the outside with another team. It has been fairly well-documented that he balked about playing nickel his first season or so, though has apparently come around about it.
I really don't want to see Mac go, but to me it would not be good to trade Waynes even with a new deal for him looming.
As much as I would like to keep guys like Sheldon Richardson and George Iloka around after this season I can imagine that the team is probably working hard to find ways to keep Barr and Waynes. I honestly wonder if they're prepared to tag Barr next season. I could see it happening.