Kopech (hamstring) is improving but isn't yet ready to return, Jesse Rogers of ESPN.com reports.

EDGE Analysis

Kopech threw off a mound Tuesday, but manager Tony La Russa said Wednesday that he still doesn't have a date for the right-hander to return to game action. While he appears to be on the right track, it's not yet clear whether the 25-year-old will require a rehab stint prior to rejoining the major-league bullpen.