Joseph Michael Nathan is an American former professional baseball pitcher. He played 16 seasons in Major League Baseball (MLB) for the San Francisco Giants, Minnesota Twins, Texas Rangers, Detroit Tigers, and Chicago Cubs. Nathan started out his baseball career as a shortstop in high school and in college for Stony Brook, but converted to a pitcher after being drafted by the Giants. He worked his way through the minor leagues, alternating between spots in the rotation and the bullpen.