Righthander Brad Penny agreed to a one-year contract with the Tigers worth $3 million, multiple reports indicate.
Penny, 32, was 3-4 for the Cardinals last season before a back injury ended his season in May.
Penny has a career record of 108-88 with a 4.11 ERA in 284 starts.
In 2007, Penny was 16-4 with a 3.03 ERA for the Dodgers. Since then, he is 20-22 with a 5.01 ERA.