Ted Roof, once a Georgia Tech star linebacker and later an accomplished assistant, is returning to Tech once more.

Roof has been hired as the Yellow Jackets’ new defensive coordinator as the full-time replacement for Al Groh, fired in October. Roof leaves Penn State, where he had coached one season, for his alma mater.

In his only season at Penn State, the Nittany Lions ranked second in the Big Ten in scoring defense (19.1 points per game), fourth in total defense (356.3 yards per game) and first in sacks (34).

“I’ve known Ted for a long time and I’m excited that he has decided to come back to Georgia Tech,” coach Paul Johnson said in a statement.  “He’s one of the most respected football coaches in the nation.”

Roof served as linebackers coach for former Tech coach George O’Leary for one season (1998) and then defensive coordinator for three. He left to become defensive coordinator at Duke in 2002 with the changeover in head coaches. During that time at Tech, he worked with Bill O’Brien, now Penn State’s head coach.

He later became Duke’s head coach 2004-07, getting fired after a 1-11 season. He was coordinator at Minnesota for one season, then coordinated the defense at Auburn 2009-11, helping the Tigers to the 2010 national championship. He left Auburn to become coordinator at Central Florida for O’Leary, but left shortly after for Penn State.

Roof used a 4-3 defense at Penn State. He said last August that "the main core is I want us to be aggressive. I want us to play fast. I want us to be physical."

In 2009, while at Auburn, he described his philosophy as using 4-3 some of the time.

"We're pretty multiple in what we do," he said. "You have to have a system that's adaptable to different types of people — especially if you're coming into a new situation. It's one thing if you've been at a place several years and you recruit to a specific system. It's another thing when you come in, you're new and you have a system that's broad enough and diverse enough to handle whatever personnel. This league, you don't trick people. You have to out-hit people. There won't be much tricking going on."

With the departure of interim coordinator/secondary coach Charles Kelly for Florida State, Johnson still has one more opening on his staff to fill.