One of the more difficult questions teams face when developing pitchers in the minor leagues is when to switch them from the rotation to the bullpen (or vice versa, in some cases). Starters are almost always the more valuable commodity, especially given the importance of rotation depth in the modern game. If a pitcher has the potential to be a starter, they should be given plenty of chances to do so.
But what is the cutoff point? Some pitchers simply profile better as relievers. Either because their raw stuff improves, or their command is subpar, or they don’t have a diverse enough arsenal to work through a lineup multiple times.