Former Penn State defensive coordinator Ted Roof said the decision to leave Happy Valley after one season was difficult after an opportunity quickly arose to return to his alma mater, Georgia Tech, for the same position.

Roof called it a "real privilege" to be part of the 2012 Nittany Lions team with first-year coach Bill O'Brien. He said in a phone interview Thursday with The Associated Press the opportunity to go to Georgia Tech only came up about two days ago.

Roof played there and also had a previous three-year stint as defensive coordinator there. He is from Georgia.

Georgia Tech has said Roof's hiring won't become official until a background check is completed, likely next week.

Secondary coach John Butler is the new Penn State defensive coordinator.