Georgia Tech lost only three starters from its 2016 defense — linebacker P.J. Davis, defensive tackle Patrick Gamble and defensive end Roderick Rook-Chungong. Gamble’s graduation, in particular, left a rather gaping hole.

In two years as a starter, Gamble gave the Yellow Jackets rugged play and leadership, putting together enough of a career that he should get a chance to play in the NFL. This spring, those toiling to follow Gamble and another graduating defensive tackle, Francis Kallon, won’t have much experience to rely upon to accomplish the task.

“We’re really, really unproven inside on defense,” defensive coordinator Ted Roof said. “Really, really unproven.”

The group of five scholarship defensive tackles under defensive line coach Mike Pelton’s supervision is among the least experienced at that position in coach Paul Johnson’s tenure. In 19 career games and 10 starts, Kyle Cerge-Henderson has made 38 tackles in his career, making him the relative veteran. The other three who have played, Brandon Adams, Desmond Branch and Brentavious Glanton, were first-year players last season and had a total of 17 tackles. The fifth returnee is Chris Martin, who redshirted.T