If they are working hard, following instructions on how OG wants to play and training well they will get their chance (Cardines and Devenney are perfect examples).
If they are not doing all three of those things they will not get their chance. Simple as that. JRS is imo unlikely to play for Crystal Palace again. From what I've heard he thinks he is better than he is and is unlikely to be handed any more chances. He's in Turkey because he's in the shop window. Its not to force his way into Palace's team. That ship has sailed