no, they have to have played in the minors for a certain number of years. also, a player on the 40 man starts to use up options - once added to the 40 man roster, a player has three option years where they can play in the minors without being exposed to waivers. Also, this has the added benefit of allowing a team to send a player back and forth between the majors and minors during those three option years. The Rule V draft is relatively simple. After being drafted and signed, a team has a certain number of years before they are required to add that player to the 40 man roster (I can't remember how long exactly since the new Collective Bargaining Agreement changed it). If that team does not add that player within that time period, that player is exposed to the Rule V draft, where other teams follow a draft format and can pick up any players put in this pool. In order for a player to remain with his new team, that team has to keep him on the 25 man roster for the length of an entire season. If the player is put on the DL, he has to make up those days with the team. If the team decides to remove the player from the 25 man roster, he is sent back to his old team.