One of the reasons that I think we'd be better trying a back 3. We need to play Williamson (although I think it would be worth trying someone like Ross out there) because we need Yeats in midfield and it means that Williamson should have a little less defending to do. Also, Mackie is better at left CB than LB and, although, for some reason he doesn't seem to be everyone's cup of tea, it would get McCann on the park.
I'd definitely go on Saturday:
PJ
Donaldson, McKay, Mackie
Williamson, Yeats, Lawal, McGinn, McCann
Oliver, Burrell
No Hetherington, no Nesbitt, no McGuffie and no Morrison. All 4 probably better coming off the bench anyway.
As it stands McKay may not be available meaning we'd need to play a back 4 anyway of course.