Some players like playing when they wired opposed to being well rested. The worse thing you can do is call up an everyday player and have him sit him for 4 or 5 days and expect him to perform for you. That's pretty much what happened with Upton. Padres sat him 2 straight games traded him here. He sat for another day. He than was in and out of the lineup for another few days before getting regular at-bats. That's extremely tough. Especially with expectations.