I'm surprised they didn't go with Slegers, but one of the reasons not mentioned so far for choosing Littell is to give him a little positive reinforcement. He and the team are all well aware that this is a one-and-done callup and he's pitching against an inferior team so it's a relatively low-pressure situation. It's much different than, for example, becoming part of the rotation replacing an injured starter during the heat of a pennant race. I hope the team tells him that and that he should just let it fly.