10-day Injured List
The 10-day injured list (known as the 10-day disabled list until the end of the 2018 season) allows clubs to remove injured players from the 26-man active roster (it was 25, prior to 2020) while keeping them on the 40-man roster. Players can be placed on the 10-day injured list for any type of injury, though players with concussion symptoms are first sent to the 7-day injured list. Players on the 10-day injured list must remain out of action for at least 10 days, though a player can also stay on the list for considerably longer than 10 days, if necessary.
Players may be placed on the 10-day injured list "retroactively," meaning the stint is backdated to the day after the last date on which the player appeared in a game. The maximum an IL stint can be backdated is three days, even if a player hasn't appeared in a game for longer than that. For instance, if a player last played on June 1 but isn't placed on the 10-day IL until June 7, the player's team can backdate the 10-day IL stint to June 4. He would be eligible to return from the IL on June 14.
After the 2018 season, the 7-day disabled list (or "DL"), 10-day disabled list and 60-day disabled list were renamed, becoming the 7-day injured list, the 10-day injured list and the 60-day injured list.
As part of the 2017-21 Collective Bargaining Agreement, the 10-day injured list replaced the 15-day injured list as the shortest option for non-concussion injuries. Baseball had a 10-day injured list at various points through its history before it was dropped in 1984.
MLB was set to bring back the 15-day injured list specifically for pitchers and two-way players (position players who are eligible to pitch in any circumstance) while instituting new restrictions on position players pitching for the 2020 season, but the rules were changed amid the COVID-19 pandemic.
Rather than a 10-day injured list for position players and 15-day injured list for pitchers and two-way players, the 10-day injured list remains in place for all players, and there is no restriction on position players pitching. There is also a separate COVID-19 injured list that has no minimum duration.