On January 3, , Clement was signed to a major league contract with the St. Louis Cardinals. The Cardinals' team doctor said that Clement was healthy and would be able to begin the season playing regularly. The Cardinals cited his recent rehabilitation and physical as reasons for adding him to the starting rotation for the 2008 season with no expected limitations upon reporting to Jupiter, Florida for spring training. However, Clement would begin the year on the disabled list after making no appearances in Spring training. On June 3, Clement made a minor-league rehab start at Single-A Palm Beach, allowing only 1 hit over six innings. He was released by the Cardinals on August 2.