Sims will start Wednesday against the Brewers, C. Trent Rosecrans of The Athletic reports.
It's unclear if Sims will be in line for more than one start. Wednesday's previously scheduled starter, Tyler Mahle, landed on the injured list with a left hamstring strain Monday, and the Reds have yet to announce a target date for his return. Sims owns an unremarkable 4.56 ERA in 16 starts for Triple-A Louisville this season but owns a solid 3.72 ERA and an excellent 12:2 K:BB in 9.2 innings for the Reds.