Cardinals' Riley O'Brien: Starting rehab assignment

O'Brien (forearm) will begin a rehab assignment with Triple-A Memphis on Friday, John Denton of MLB.com reports.

O'Brien has been shelved since Opening Day due to a strained forearm but has finally been cleared for a rehab stint The 29-year-old has completed three live batting practice sessions and could rejoin the Cardinals' bullpen before the end of July.