Flaherty (shoulder) will begin a rehab assignment Wednesday with Triple-A Memphis, Derrick Goold of the St. Louis Post-Dispatch reports.
Flaherty is expected to throw 30-to-35 pitches Wednesday in his first rehab outing and will ramp up his workload in subsequent appearances. The 26-year-old began the season on the IL with a shoulder strain and made only three starts in June before returning to the shelf. Assuming Flaherty avoids any further setbacks, he should rejoin the Cardinals' rotation in late August or early September.