Matz will start Tuesday's game in Milwaukee, Derrick Goold of the St. Louis Post-Dispatch reports.
Matz was activated from the 60-day injured list Sunday and was available out of the bullpen later that day for the Cardinals' 14-7 win over the Yankees. He was not used, however, and the team has opted to give him a spot start while they push other rotation members back. Matz seems likely to shift back to a relief role after Tuesday's outing, although it's possible he earns additional starts if he pitches well.