Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Mark John Hamburger (born February 5, 1987) is an American professional baseball pitcher for the Texas Rangers of Major League Baseball. After going undrafted in the 2007 Major League Baseball Draft, he signed with the Minnesota Twins. Hamburger was traded to the Texas Rangers for Eddie Guardado on August 25, 2008. Hamburger was called up to the majors for the first time on August 30, 2011. Major League Baseball (MLB) is the highest level of professional baseball in the United States and Canada, consisting of teams that play in the National League and the American League.