Matz (shoulder) and the Cardinals won't face the Reds on Sunday after the game was postponed due to inclement weather in St. Louis, John Denton of MLB.com reports.
Matz, who was reinstated from the 15-day injured list Sunday, will thus have to wait until after the All-Star break to make his first start with the big club since May 22. The Cardinals and Reds will make up the postponed game Sept. 17 as part of a split doubleheader.