Clement missed last season while recovering from shoulder surgery. He last pitched for the Boston Red Sox in 2006.
The 33-year-old right-hander is 87-86 with a 4.47 ERA in nine major league seasons with the San Diego Padres, Florida Marlins, Chicago Cubs and Red Sox. An AL All-Star in 2005 with the Red Sox, he made at least 30 starts in each of his first seven full big-league seasons from 1999-2005 before shoulder problems limited him to 12 starts for
Boston in 2006.
Cardinals general manager John Mozeliak said Clement is physically ready to pitch and "can be a solid addition to our starting rotation."
After winning the 2006 World Series, St. Louis struggled with a makeshift rotation last season and slipped to 78-84. The Cardinals finished with a 4.65 ERA, ranking 11th out of 16 NL teams.
Clement gets a $1.25 million salary this year and can earn an additional $5.25 million in performance bonuses, receiving the full amount if he pitches 200 innings.
The Cardinals have an $8.75 million option for 2009 with a $250,000 buyout. The option would increase to $9 million and the buyout $500,000 if Clement reaches 160 innings this season; $9.5 million and $1 million for 180 innings; and $10 million and $1.5 million for 200 innings.
The option would become $11 million and the buyout $2 million if Clement finishes in the top five in 2008 Cy Young Award balloting.