Every NBA team knows the value of depth over the course of a long, 82-game season, which means every roster spot is likely to matter at some point. The Celtics took another step toward finalizing their roster on Wednesday, announcing they have agreed to a two-way contract with second-round pick Dillon Mitchell. With Mitchell under contract, joining Amari Williams, the Celtics have only one more two-way roster spot available. Here's a look at how Mitchell's signing clarifies the battle for the Celtics' final roster spot. Who could get the Celtics' final roster spot?