The Rockies returned Rule 5 pick Petit (elbow) to the Tigers on Tuesday.
The Cardinals acquired Rivera from the Red Sox on Tuesday in exchange for Juan Garcia, Andrew Parker of SoxProspects.com reports.
Stanek is expected to have his one-year option declined by the Cardinals, Daniel Guerrero of the St. Louis Post-Dispatch reports.
Flaherty (forearm) was reinstated from the 15-day injured list Sunday and struck out one batter while allowing one hit and no walks over two scoreless innings in the Tigers' 4-2 loss to the Pirates in the season finale.
Cardinals president of baseball operations Chaim Bloom said Monday that Walker was playing through some hip pain and other discomfort late in the season, Derrick Goold of the St. Louis Post-Dispatch reports.
The Tigers optioned Hurter to the rookie-level Florida Complex League on Sunday.
Cardinals president of baseball operations Chaim Bloom said Monday that Fitts (lat) is on track to be ready at the start of spring training but will have his workload monitored, Derrick Goold of the St. Louis Post-Dispatch reports.
Madden tossed three scoreless innings of relief with three strikeouts in Sunday's 4-2 loss to the Pirates.
Valencia went 1-for-4 with a solo home run in Sunday's 4-2 loss to the Pirates.
Ryan (0-1) took the loss against the Pirates on Sunday, allowing two runs on three hits and two walks with three strikeouts over 1.1 innings.
