The Reds bullpen has been hit hard by injuries, forcing them to move Cuban fireballer Aroldis Chapman back to the bullpen after stretching him out as a starter during spring. Newly signed closer Ryan Madson is out for the year after undergoing Tommy John surgery, Nick Masset will start the season on the 15-day DL, and lefty Bill Bray is still getting on track after missing most of the spring with a strained groin.
Simon, 30, posted a 4.90 ERA with a 2.08 K/BB ratio in 115 2/3 innings pitched last year with Baltimore. He appeared in 23 games, 7 of them as a reliever. He has a 44.7% ground ball rate and an average fastball velocity of 94.5 MPH in four seasons with the Orioles.