The way I see it is that Sparky chooses the Setup guy instead of the LHS is because if you have a lead in a certain inning, the Setup guy is likely a better pitcher than the specialist. If Milacki was set as a specialist in the 8th inning and the 8th inning setup guy is a lefty, you'd likely see Milacki enter the game a lot more because (1) he will be the better pitcher for Sparky to choose from than those that are also available for that inning, and (2) most hitters in OLs are righties.