Miley (shoulder) was scheduled to throw a bullpen session earlier Thursday, Maddie Lee of the Chicago Sun-Times reports.
The Cubs have yet to reveal how Miley felt coming out of the workout, but the fact that he isn't being shut down from throwing four days after landing on the injured list suggests that his strained left shoulder isn't a long-term concern. Chicago replaced Miley in the rotation with Matt Swarmer, who will pick up his second start in Saturday's doubleheader with the Cardinals after limiting the Brewers to four runs over six innings Monday in his MLB debut.