Seems that McKay has dropped a few of the regulars and gone for a few uncapped guys but sadly for Coutts and Fleck, they are strong - for Scotland - in centre mid with the two experienced lads of Scott Brown and Darren Fletcher retained. Even if one of both of them retired, you've still got a long list seemingly in front of them: James McArthur of Palace and Charlie Adam from Stoke, Bannan from the pigs, Tom Cairney of Fulham, Kenny McClean from Aberdeen, John McGinn from Hibs, Callum McGregor of Celtic and that's not mentioning Kevin McDonald! All of that long list have been capped recently - minus Charlie Adam, so I don't think we'll see Coutts or Fleck get a call up, unless we get promoted.
As others have said, it gives them a break each international break and they certainly deserve it!