Carpenter made his Major League debut on June 4, 2011, starting at third base and batting seventh. During his brief stint in the Majors that year, he played seven games, collecting one double, a .067 batting average and four walks. The Cardinals qualified for the postseason by clinching the wild card, but left him off the postseason roster. St. Louis became the World Series champions when they defeated the Texas Rangers. In spite of his scant contributions to winning the Series, the Cardinals awarded Carpenter a championship ring.