A player to be named later in an MLB trade must be named within six months. The arrangement lets two clubs complete the main portion of a trade while postponing the identity of one player or substituting another agreed form of compensation.
Teams use a PTBNL when they need more time to evaluate minor-league talent, decide which position to fill, or resolve transaction restrictions. The receiving club and the trading club commonly agree on a short list of eligible players, from which the final player is selected later. If they cannot agree, cash or another consideration can replace the player.
The six-month limit applies to closing the deferred portion of the trade, not to a vague promise that can remain open indefinitely. A PTBNL is usually a minor-league player, although the rules govern who may be included and when the player can legally move. The device became especially useful around older waiver procedures, when a player acquired after the non-waiver deadline might need to clear waivers before being formally transferred. It should not be confused with a draft pick or an unnamed free-agent signing.