Siemian (shoulder) was listed as a limited participant at Monday's practice, Ricky Henne of the Chargers' official website reports.
It's unclear exactly what Siemian did, as the Broncos held a walk-through practice without any pads. Regardless, it's already been reported that the second-year quarterback is expected to return for Thursday's game in San Diego. Rookie first-rounder Paxton Lynch struggled in Sunday's loss to Atlanta, leaving Siemian as the unquestioned top quarterback so long as he stays healthy.