Simon is dealing with a shoulder injury that has seen no improvement despite receiving medication, Zach Buchanan of the Cincinnati Enquirer reports.

EDGE Analysis

Simon most recently pitched Wednesday, giving up five hits and three earned runs during just one inning of relief work. It's unclear if he's headed for a DL stint or a demotion, as the 35-year-old currently sits with a 9.45 ERA and 2.06 WHIP over 53.2 innings.