Richan (undisclosed) was released by the Tigers on Friday, Emily Waldon of Baseball America reports.
The 25-year-old began the season on the injured list at Double-A Erie with an unspecified injury, and he's now been let go after appearing in three rehab games at Single-A Lakeland. He made eight starts for Lakeland last year and had a 3.72 ERA, 1.17 WHIP and 26:9 K:BB over 29 innings.