Hecking left to take over at Bundesliga rivals Wolfsburg on Saturday and Nuremberg have moved quickly to install under-23 coach Wiesinger and assistant coach Reutershahn in a joint management role.
The duo's official presentation will be at an opening training session on January 3.
"We went over all the options intensively and concluded that FCN would approach the second half of the campaign with this set-up," sporting director Martin Bader told club website fcn.de.
"In Michael Wiesinger and Armin Reutershahn we have two coaches from our own ranks that enjoy a great amount of trust and acceptance."
Wiesinger added: "FC Nuremberg is my club; I was a player here and have put my heart and passion into my work here.
"To get the chance to take on this sporting challenge is very special for me. It's a task that I trust myself with because I know the club and the setting very well."
Hecking left to take charge of Wolfsburg as the replacement for Lorenz-Gunther Kostner, who had been in caretaker charge since Felix Magath's resignation at the end of October.
Wolfsburg are 15th in the Bundesliga standings on 19 points, one behind 14th-placed Nuremberg.