Sometimes happens that I want coach to let decide which players has to pick for a certain position. So I leave these positions empty.
For example, Im training driving, so I fill SF and PF position startup and bench. There are like 2 players in advance for which I will have another role, because they lack more minutes than others. However if I let 2 empty places left for the coach to decide, he might use for these even players which already have a role.
So I would like to tell him that these players cannot be used for other positions.
Also there could be really helpful option to fill the bench (or startup) position specifically by coach. So if there would be like 4 available players in the roster, he could choose whatever he want just for that marked position. This could be great for lineups where you have only starter, however doesnt care about who will play the bench.