Despite this success, Isringhausen's 2006 season began with two losses and a blown save in his first five appearances. He struggled with control problems throughout the season, leading to 38 walks (the most given up by Isringhausen in a season since he became a closer) and a 3.55 ERA, which was his highest ERA as a closer since the 2000 season, in which his ERA was 3.78. Isringhausen finished the season with a 4–8 record and 33 saves along with 10 blown saves. He missed the entire 2006 playoffs due to a hip injury, allowing rookie Adam Wainwright to become the Cardinals' closer for the playoffs and that team's World Series Championship.