From the St. Louis beat writers blog

Rotation Adjusted: The Cardinals will activate Jeff Suppan from the disabled list Sept.1 to start the series finale against the Houston Astros. The move allows rookie lefthander Jaime Garcia to start the Sept. 3 series opener against the Cincinnati Reds followed by Chris Carpenter and Adam Wainwright La Russa formalized* the move on Saturday after watching Garcia throw 5 1/3 scoreless innings in Friday's 4-2 win over the Nationals. He could have chosen to keep Garcia on regular rest, have Carpenter and Wainwright work the first two games, then employ Jake Westbrook in the third game. Garcia, Carpenter and Wainwright started during the Cardinals' three-game sweep of the Reds in Cincinnati Aug. 9-11.