Designated for Assignment (DFA)
Sometimes a club wants to remove a player from its MLB Reserve List (40-man roster), but it has to be done immediately because the player's roster slot is needed. Or sometimes a club wants to remove a player only from its MLB Active List (25-man roster), but Optional Assignment Waivers must be secured before the player can be optioned to the minors. In those cases, a club can place a player on the Designated List.
When a player is placed on the Designated List (and is "Designated for Assignment"), the "Designated Player" is removed from his club's MLB Reserve List (40-man roster), and then the club has up to ten days to either trade, release, non-tender, or outright the player to the minors. A club can also return a Designated Player to the 40-man roster and either option the player to the minors or reinstate the player to the 25-man roster, as long as the Designated Player is not replaced on the 40-man roster by another player while the player is on the Designated List. (A club might have to DFA a player to buy time while it attempts to secure Optional Assignment Waivers).
A player on Optional Assignment to the minors must be "Recalled - Not to Report" before he can be Designated for Assignment.
The player continues to be paid and the player accrues MLB Service Time while on the Designated List.
Also, a player acquired off waivers can be placed back onto Outright Waivers by his new club and can be outrighted to the minors if he is not claimed, but if a club acquires a player off waivers and the claiming club's 40-man roster is full so that the club needs to remove a player from its MLB Reserve List in order to open a spot on its 40-man roster for the newly-acquired player, the player who was claimed off waivers cannot be the player who gets "Designated for Assignment."