Georgia Tech defensive coordinator Ted Roof was not in a word-mincing mood Tuesday.

Following the Yellow Jackets’ practice in preparation for the ACC opener against Virginia Tech, Roof seemed as agitated by the defense’s play in the second half against Georgia Southern as he likely was after the game.

“Second half, embarrassed, disappointed and got to get better real quick,” Roof said.

In the third and fourth quarters against Georgia Southern, Tech gave up 28 points and 398 yards of offense after holding the Eagles to 10 points and 130 yards in the first half. Tackling, effort and focus were all problematic.

“We’ve got to learn to strain for four quarters,” Roof said. “We’ve got to have extreme attention to detail and play with fanatical effort.”

Roof said the plan is to play more players against the Hokies, given that they’ve averaged almost 80 plays per game through their first three games. Playing slower-tempo teams while its own offense has played at a methodical pace, Georgia Tech’s defense has been on the field for 60 plays per game. That could mean playing time for defensive linemen Tyler Merriweather and Francis Kallon, among others.

“Guys can’t play 80, 90 plays like we did last year,” Roof said. “We’ve got to rotate guys and sub guys. With that comes some growing pains, but at the same time, you develop depth and that’s what we’ve got to do.”

This has been a week, Roof said, for returning to fundamentals like playing with effort through the whistle and tackling with better form. The defense has worked “extremely hard,” Roof said, on using proper tackling technique this week after several missed tackles against Georgia Southern.

“From here on out, we’ve got to wrap everybody up,” Roof said. “We’ve seen what happens when we don’t.”

Defending deep passes is another area of concern. Against Georgia Southern, cornerbacks D.J. White and Lawrence Austin were in position but beaten for pass plays of 68 and 43 yards, respectively.

“We really pressed on that, too, because we kind of got off our technique a little bit last game and kind of let some things go over our head that shouldn’t have,” cornerback Chris Milton said, “so we’re really going back to the basics and covering that.”