Sims was optioned to Triple-A Gwinnett on Tuesday.
Sims was likely unavailable for a couple of days after tossing 2.1 innings during Game 2 of Monday's doubleheader, so he was sent to the minors to open up a roster spot for Tuesday's starter, Anibal Sanchez, who returned from the disabled list in a corresponding move. Sims should be back with the big club when a fresh arm is needed again.