When dropping a player, the verification to drop should be to type word yes
Technically this is not a software feature, is more like a design bug. For the last 3 years on my league, we have had someone drop a player by accidentally clicking drop button on player profile and then accidentally clicking the verification button that is placed on the same position in the UI. It happened to me twice, and in our league, managers are respectful and allow the managers to regain their player but in other leagues this might not be the case.
After researching here http://forums.rotoworld.com/topic/35880-what-should-happen-if-a-valuable-player-is-dropped-by-accident/, 25 percent of managers believe that player is up for grabs. Changing this behavior and adding a 'yes' verification typed by the user will allow your app to be more robust.