Now, I have an IMPORTANT QUESTION:
I see that players with high stamina barely rest a few minutes (they play around 44 minutes), even when they have a backup only for his position (I think this is another screw up by Marin).
But now it seems that this will make their performance worse.
So, what can we do to get our high stamina player rested during a game? It seems that there is nothing we can do...
It has something to do with the ingame rating. I don't know, do you know the old LCD?
You could set a blank line up, set "let coach decide" and play the whole time with the best possible roster. According to your skills, offense, defense, stamina every player has some kind of ingame rating. In the old LCD, the best five players played on their positions. As soon as the clock stopped, the line up was changed and set up according to this ingame rating. It was a nonstop imprivement of your line up during the game.
Now take two players, Player A and B.
Player A has high stamina and Player B low. Player B has also worser skills than Player A and is his back up. With this, the high stamina prevents Player A from beeing subbed out. Player B will stay almost the whole time at the bench.
Sometimes you see the opposite, if you have a younf trainee with stamina 1. He should play 48 minutes but gets only 44 or 46, because at the end of the game, he is so bad that the engine takes him out.
So to answer your question: you need back ups with better skills and/or high stamina.