The only thing I know to do would be to either release them from the teams. If you do that, then there won't be enough player slots to create new players. The other option is to change the draftees to real players along with their attributes. Either way it would be time consuming and probably not worth the effort. Hopefully, again, some of the older more experienced roster makers from the past can shed some light and a fix to this. I'm out of ideas and I don't worry about the minor league players unless a fake one pops up in the majors. I check my lineups and rotations periodically but not a fanatic about day to day roster moves with the real day to day moves and injuries.