The 40-man roster is also called the expanded roster, its composed of all the players in a Major League club's organization who are signed to a major-league contract. These are the players who are able to be called up to the 25-man roster at any given time. Any players on the 15-day disabled list or minor leaguers with a major league contract who are assigned to the minors under an "optional assignment" are also on the 40-man. (Each player has three option years to be sent to the minors if he is added to the 40-man roster before being waived.)