Norwich caretaker boss Alan Irvine said he was "really disappointed" to see technical director Ricky Martin leave.
Martin has left in a shake-up that has also seen head of football recruitment Tony Spearing and head of scouting Lee Darnbrough also depart Carrow Road.
The changes come a week after Stuart Webber was named sporting director.
"Ricky's worked here for 16 years, was instrumental in building the academy and the number of young players that have broken through," said Irvine.
He told BBC Radio Norfolk: "Changes happen. From a personal point of view I'm really disappointed to see him go. I've spoken to him, and wished him good luck and have no doubt he'll pop up somewhere else.
"He was instrumental in me coming here so I've got a lot to thank him for."