Katz, an infielder who played at Louisiana State, will report to State College, Pa., the Cardinals' short-season Class A affiliate in the New York-Penn League.
Farinaro, a right-hander out of Head-Royce School (Calif.), will join the Gulf Coast League Cardinals in Jupiter, Fla..
The Cardinals have now signed their first 29 selections through the 28th round.
Quinn Roberts is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.