The IR spot is the Injured Reserve designation employed by some fantasy basketball leagues. In leagues where an IR spot is enabled, owners can give injured players this designation, which temporarily removes them from the roster, freeing up a spot to add another player.
Typically, for a player to be eligible for an IR spot, they must miss a certain number of games or be dealing with a serious injury. Overall, the goal of the IR spot is to allow roster flexibility to fantasy owners while players are injured and unable to produce.