I have D.Brown on my team and he's on the DL7 and I can't place him in the DL slot. How come?
It is because he is on the 7-day DL and your commish has the minimum
set for the 15-day DL - fleaflicker.com - if you hover over the DL, you can see that it says 15 day as the first listed (minimum requirement).
We also added the answer to this and many more in our new Owner's Manual: fleaflicker.com