I suspect Wright will get his first league start with Kent dropping out.
Roofe and Hagi in for Morelos and Aribo.
McLaughlin in for McGregor to give him some gametime.
Outside of those 4, I could see one of Simpson, Bassey or Zungu starting. But no more than one of these 3. Anymore and It would be too many changes and could result in a St. Mirren like performance and result.
Ifs buts maybes as far a what st Johnstone may do, we should focus on our priorities as play accordingly. SG did mention the unbeaten season so it is obviously a goal along with SC so would expect 3 of the suns bench to feature. Of course we may have options limited due to the covid hearing but playing as strong as sensible will be the way. Can see Weight for Kent, Roofe for Morelos and Hagi for Aribo. Not many other options further back.