Haden, in comments to the USC Trojans' official website, said one impostor contacted former NFL head coach and current NBC broadcaster Tony Dungy while another reached out to the Denver Broncos coaching staff.
USA Today reported the likely target of that hoax was Broncos defensive coordinator and ex-Jacksonville Jaguars head Coach Jack Del Rio.
Dungy told a syndicated sports talk radio show he had no interest in the job, prompting a response and investigation by Haden.
"Tony's discussion on the radio today of being contacted by USC was a complete surprise to us," he said. "So were the calls made to the Broncos. I can assure you no authorized representative of USC or our athletic department made these calls."
The AD said the perpetrator of the call to Dungy had been identified and contacted while the Broncos caller had also been identified.
Haden fired head Coach Lane Kiffin last week after a 62-41 loss to Arizona State that dropped USC to 3-2 on the season.
Assistant Ed Orgeron was named as the Trojans' interim coach through the remainder of the season.