Hagen spent the 2006 season at Fresno State as the offensive coordinator for the Bulldogs.
According to a UNC official reached Tuesday afternoon, no new football staff members have been officially hired yet at UNC.
Fresno State coach Pat Hill confirmed the news in an interview with the Fresno Bee.
"Any time a guy can improve his career, that's a good thing," Hill told the newspaper. "I hate to see guys leave. But I've got no problem seeing guys move on and better their career and make more money. If they get that kind of opportunity, they have to take it. I can't pay them like these guys pay them. If you got a $80,000-100,000 raise, wouldn't you leave?"