Baseball players who are injured may be placed on a disabled list, similar to the injured reserve status for football players. Unlike the injured reserve status, however, this list does not preclude baseball players from returning to active status during a season.
There are two different lists: a player can be placed on a 15 day or a 60 day disabled list, depending upon the extent of injury. Since baseball teams maintain a roster of eligible players, a temporary placement on the list means that a team can reconfigure its roster and invite healthy players to fill in for the injured player.
If a player is on a 60 day disabled list, the team will usually look for a replacement player outside of its team. They might fill the roster with a minor league member, or they might be able to replace the empty space on the roster with someone who has been injured and is now recovered.
Major league baseball teams are limited in their roster to 40 players, so it is sometimes necessary to put a seriously injured player on the disabled list in order to get around the 40-man limit. The person is only considered off the roster if he is on a 60 day disabled list, however.
Sometimes, it is valuable not to put a player on a disabled list. A key player, who might be able to play in a few games, is usually not listed on the chance that he will be able to rejoin his team quickly. If the extent of the injury suggests that player will really need time off to recover, however, then the team must be able to fill the roster with active and uninjured players.
Usually, the 15 and 60 day disabled lists mean that an injured player cannot return to the team before the length of days specified. Unless the player has an injury that is likely to affect him for the season, placing a player on the shorter list is preferable.
The days counted begin with the player’s first missed game. So if a player has been unable to play for a week prior to being placed on a 15 day disabled list, he would technically be able to play again in eight days.