The 2019 Rule 5 draft isn’t until Dec. 12, but the protection deadline is tomorrow at 5 p.m. PT. This means that teams have a little over 24 hours to add eligible players to the 40-man roster in order to protect them from the draft.
In a nutshell, the Rule 5 draft helps prospects make it to the big leagues. Once a player reaches either four or five seasons of minor league service (depending on their age when signed) they must be added to the 40-man roster or else they will become eligible for the draft. At that point, any other team can select the player.