Liberatore will start Sunday's game against the White Sox, John Denton of MLB.com reports.
All 12 of Liberatore's appearances this season have come in relief, so while he did throw three innings in an April 28 appearance, the Cardinals are most likely treating Sunday's contest as a bullpen day. However, it's possible Liberatore could fill a more traditional starting role moving forward if he pitches well Sunday, as the Cardinals have an opening while Steven Matz (back) is on the 15-day injured list.