I don't think Braun is slacking. He's showing the effort. He's just hurt. I don't know if you've ever played baseball. But having a thumb injury makes it very difficult to grip a bat, and every time you swing, whether or not you make contact, you're putting torque on it. That's why even giving him the day off, but pinch hitting him, basically is the same as if he played the entire game. Any swelling on the thumb will flare back up as soon as he swings the bat.