Schreiber (knee) threw a bullpen session Thursday and is scheduled to throw off a mound again Sunday, Anne Rogers of MLB.com reports.
Schreiber has been progressing well from a right knee patella tendon injury he sustained in late July. While he's feeling good from a pitching standpoint, he'll need to do more fielding work before the next step in his rehab is determined. Prior to the injury, Schreiber tallied a 4.14 ERA across 37.0 innings out of the bullpen.