John Claiborn Mayberry, Jr. (born December 21, 1983) is an American professional baseball outfielder who is currently a free agent. He attended high school in Kansas City, and in the 2002 Major League Baseball Draft, the Seattle Mariners drafted him out of high school (28th overall). However, he chose not to sign, instead attending Stanford, where he played three years before being drafted again. He also played for the United States national baseball team at the World University Baseball Championship in 2004. The Texas Rangers selected him in the 2005 Major League Baseball Draft (19th overall). He played for the Philadelphia Phillies, Toronto Blue Jays and New York Mets.