Baseball teams tend to put most of their players on the waiver wire each year just to see if they'll clear or if a decent trade presents itself when the player is claimed. If the team decides they don't like the deal they'll just pull out. A guy I played baseball with was a staunch believer and recommended the ol' pull out method even after three unplanned pregnancies but that's neither here nor there. Chase Headley was claimed by an unknown team sometime in the last few days and the Padres pulled him back making it impossible to trade him for the rest of the season.