Pitcher is “player to be named later” in trade for John Axford.
Sam Freeman has appeared in four games this season.
This move lines Joe Kelly up for the start on Sunday.
Curtis was batting .259 for Memphis this season, hitting four home runs with 42 RBI.
Tyler Lyons is slated to start game two of the twin bill.
Cardinals promote righthanded pitcher from AAA Memphis and demote Friday night’s starter.
All four players were purchased from Springfield (AA).