Obviously this is a bit "if yer auntie had baws" but if Patterson's played a very bit part for St Mirren/Livingston/Dundee but can't hold down a spot in their first team then nobody gives a f**k that he's not playing for Scotland. A quick glance at Transfermarkt would suggest he's played a total of 5 games in the top flight here. Yes he scored in Europe. Yes he looks like a very talented player. But you can't, with a straight face, say that the number of games he's involved in at club level merits being a nailed on starter in the national side.
Also Gallagher was absolute dugmeat for a year at club level.