In Major League Baseball, the disabled list (DL) is a method for teams to remove their injured players from the roster in order to summon healthy players.
Players are placed on either the 15-day or the 60-day disabled list, usually depending on the severity and/or recovery time of the injury. A player may be shifted from the 15-day to the 60-day DL at any time, but not vice-versa. The player may not rejoin the team until 15 or 60 days has elapsed; however, a player's time on the DL may exceed the specified number of days, and, further, if a player is transferred to the 60-day DL after August 1, he may not return to the active roster that season.
The 15-day DL does not count the player on the active roster (comprising the 25-man roster until September 1), whereas the 60-day DL does not require the player to be counted on either the team's active roster or its 40-man roster; however, a team's 40-man roster must be full in order for the option of a placement on the 60-day disabled list to be available.
Placing a player on the disabled list opens a spot on the active roster. Another player from the minor leagues, free agent pool, a traded player, or a recovered player coming off the disabled list may be used to fill this spot. This allows a team to avoid being penalized because it avoids the disadvantage of playing with a reduced roster.
Retroactive placement may be made at most 10 days after the time of injury. When a player is listed as day-to-day before being placed on the disabled list, it therefore may pinpoint the date of the injury.
Starting with the 2011 season, Major League Baseball has instituted a new disabled list, a 7-day list specifically for concussions and brain damage. The idea is to prevent long-term brain damage which may take up to 7 days instead of using the full 15 days by current standards. MLB has ensured this is only for concussions, and will take steps to avoid abuse of the system. If a player is not activated from the concussion DL after those 7 days have passed, he is automatically transferred to the 15-day DL.
Also in 2011, Major League Baseball has instituted a paternity leave. This allows a team to replace a player who is an expectant father for 1–3 days on the roster to be available for the birth of his child.
A player may be placed on the bereavement list upon attending to a seriously ill member in the player's immediate family or to a death in the family. The bereavement list may span from a minimum of three to a maximum of seven games.
Minor League Baseball
Minor League Baseball uses a 7-day disabled list for all injuries. Players who are on the 40-man roster but get hurt in the minor leagues are placed on the minor league DL, but not on the major league DL. One problem this poses is that a player who is injured in the minors and who would be placed on the major league 60-day DL cannot be placed on the 60-day, meaning the 40-man roster spot is not freed up.
The freed-up roster spot can be strategically valuable, leading to occasional creative use of disabled lists by MLB teams and their affiliates (similar to teams appealing or dropping the appeal of a suspended player to maximize player contribution). Players who are performing poorly and are slightly injured might be put on the DL so they can go to the minors on rehab, when the MLB club might only want them in the minors because they are playing poorly. There are rules against blatantly "gaming the system" in the Collective Bargaining Agreement between the players and the league.
A team may keep an injured player on the roster but keep him listed as 'day-to-day' to indicate that the medical staff is unable to determine when the player can resume normal playing activities again. If the injury turns out to be minor, then the player may resume playing without having to wait to come off the disabled list; however, depending upon the circumstances, the team may find itself effectively shorthanded in the meantime.
Players recovering from an injury may appear in a limited number of minor league games while still on the disabled list in order to prepare for reactivation. Non-pitchers may stay in the minor league club for up to 20 days; pitchers for up to 30 days.
Until the late 1980s, there were 10-day and 21-day disabled lists. The number of players who could be placed on each list was limited, and there was much less flexibility about when they could return to action. In addition, players with major league contracts were not allowed to go to the minor leagues for rehabilitation.