I was working my depth chart yesterday and found a few players that were not assigned into any places - which made me realize that there really was no way to see that you have all your players somewhere in your depth chart. I have added a roster view that lists players who are currently not in your depth chart. If you switch to that view in your roster and find any players in the list, you can open their player card and click on the "Details" tab; at the bottom there is a link "Assign into depth chart" that you can use to place the player into your depth chart. Then you will be able to see him next to any other players you have in the depth chart and modify your DC accordingly.