The White Sox optioned Dunning to their alternate training site Thursday.
Dunning will head back to Schaumburg after turning in a solid-but-unspectacular MLB debut in Wednesday's 5-3 win over the Tigers. He worked 4.1 innings in the start, giving up three runs on five hits and a walk while striking out seven. The White Sox have a pair of off days coming up next week, so the team will be able to get by with a four-man rotation until Sept. 1. Unless either Carlos Rodon (shoulder) or Reynaldo Lopez (shoulder) is back from the injured list by that point, Dunning should be the leading candidate to step back in as the White Sox's fifth starter.