I think he needs four or five 90 minute games injury free under his belt. However this rightly should only come when one of the current first 11 are injured, suspended or their loan/contract ends. He has no devine, right to play.
Barton seems to be taking the limited opportunities he has been getting, so it will be the same for him.
It's great that we have players with such ability on the bench.
I do feel the likes of Cody, Barton, Fleck, Cameron, Clarke, Hussey would be automatic choices in many (not all) other league one teams. We are in a great position.