Setting up the call of the players for their nation

[DMaster2]

I'm trying to make a custom world cup, but i have problems with international call-up duty (or however it's called in english). In my current world league, the game is asking me to call 23 players to play ALL the games in the competition (which is setted up so it stretches through the year, making impossible to save a single team for a whole year due to injuries and stuff). How do i change it so it asks for the players before each "international week" like it works in the normal game?