Last year I needed to swap out some players on my team with free agents, but it ended up being more complicated than I was used to in FF leagues. Rather than simply dropping my player and then just adding a free agent to fill the slot, there was some kind of bidding process. So I picked the FA I wanted bidded something, and not sure how it works, was not successful. But there was a several day delay before I knew it wasn't successful (I guess waiting for everyone to bid on their various FA picks?). So I ended up with empty or dead slots on my team, because I wasn't sure how to properly maintain it.