Riordan signed a minor league contract with the Tigers on Monday, Matt Eddy of Baseball America reports. Riordan's return to the U.S. produced passable results, as he posted a 3.58 ERA and 1.07 WHIP in five starts with Triple-A Toledo, although he did experience some struggles with Double-A Erie. Until the right-hander can be more consistent against upper-level hitters, he'll likely continue to act as organizational depth.
The Rockies outrighted SP Cory Riordan to Triple-A Colorado Springs, removing him from the 40-man roster. He spent nearly all of the 2011 season with Double-A Tulsa, going 1-12 with a 5.37 ERA.