Long (back) was activated from the 10-day injured list Tuesday, Susan Slusser of the San Francisco Chronicle reports.
Long has been on the shelf about three weeks with a back strain and will rejoin the active roster after covering one inning during a rehab appearance in the minors. The 26-year-old was working as a starter prior to the injury, but he'll be available out of the bullpen with San Francisco's rotation currently in good health.