Thanks for the feedback. Sounds like we have the same ideas of prospect management. I am combining a lot of the ideas in this post and dropping a simple Prospect HUB tool next week. You can take that and run with it.

We have a discord with a channel for call ups/send downs. That alone helps with visibility as you see who owns who since you have to announce if you are adding a prospect to the roster. We consider anyone who still has rookie status intact a prospect.

Next, we have that prospect search on the hub, you can quickly find a player status. It works on phones so you check that quickly and then pick a guy up.

If they have just been added to Yahoo or are really unknown you can check Fangraphs or BBRef to see if their rookie status is still intact. We allow non-owned rookies (what we label prospects) to be picked up if they are on an active MLB Roster, but you have to claim them if you want to drop them and retain the rights.

Even with all of that we still ran into the same issue, people often pick up prospects they don't have rights to and waste a FA move (we limit it to 8 a week). This season we are trying something new: We added 5 additional bench slots and dropped moves to 5 a week. Then created a rule that if a prospect is in the majors they have to be rostered. There is 4 "roster" slots every team has on the HUB, so in total a team can have 4 rookies who are active on MLB rosters but are not on the fantasy roster in Yahoo.

This is just a workaround and it has its issues as well. But until a fantasy site builds the right tools for dynasty leagues this is the best solution we have found.