Smith (elbow, shoulder) threw a bullpen session Friday, Jen McCaffrey of MassLive.com reports.
This was the third time Smith has thrown a bullpen session since the All-Star break, and he's expected to throw another two sessions. After that, the Red Sox will aim to have him face live batters. He'll still need a rehabilitation assignment, so his activation off the disabled list is not expected until early-to-mid August.