The Basics: What is the 40-man roster?

The 40-man roster, or Major League reserve list, is the collection of all players who are currently signed to Major League contracts (with the exception of players on the 60-day DL or temporary inactive list). It includes players on the active roster, players on the 15-day DL, and players on optional assignment in the minors. Every transaction involving the active roster of the Major League club has to take into consideration the state of and effect on the 40-man roster. Players can be temporarily removed from the 40-man roster by being placed on the 60-day DL. Players are permanently removed from the 40-man roster when they are designated for assignment (or DFA'd), and can only be re-added if their contracts are once again purchased by the Major League club. Examining a team's 40-man roster can provide a good deal of insight into the team's overall roster flexibility (open spots, players with options, 60-day DL candidates, etc), as well as which specific players are most likely to be called up to the big leagues should a need arise.