Sims was traded from the Braves to the Reds along with Matt Wisler and Preston Tucker in exchange for Adam Duvall on Monday.
Sims appeared in just six games at the big-league level for the Braves in 2018, accruing an ugly 7.84 ERA and 1.94 WHIP with 10 strikeouts over 10.1 innings out of the bullpen, though the Reds are confident they can shape him into a starting pitcher. He was optioned to Triple-A Gwinnett on June 26. It's unclear if he'll report to the minor leagues after being shipped to Cincinnati.