ATLANTA — Georgia Tech coach Paul Johnson still has confidence in his defensive coaches following one of the worst showings ever by the unit.
    The Yellow Jackets gave up the second-most yards in school history in last week's lopsided loss at No. 15 North Carolina. Georgia Tech's defense has another tough challenge at No. 18 Virginia Tech on Saturday.
    The search for improvement on defense has been a constant theme for Johnson this season. He said Tuesday a review of last week's 48-20 loss to North Carolina solidified his belief that defensive coordinator Ted Roof's scheme is sound and the players aren't confused.
    "I watch the tape repeatedly over and over and I watch it with the defensive coaches and I understand what's happening," Johnson said, adding he has faith in the defensive scheme. "... As long as it's sound as you've got a chance to execute it, that's all you can ask of them."
    Georgia Tech has allowed 34 or more points in four of its last five games. The defense gave up 636 yards to North Carolina last week, second only to the school-record 667 allowed against Notre Dame in 1977.
    The Yellow Jackets rank last among the nation's 128 FBS teams in third-down defense. Opponents have been successful in converting 52 percent of third-down plays.
    Johnson said defensive players have not lost faith or lack an understanding of the system.
    "I don't think we have those problems," he said. "I've had those before where the kids would come and say coach you've got to help us. That's not the issue. We're not having those problems. We've just got to play better."
    The defense's inability to get off the field on third down has been the biggest weakness.
    "That creates most all the problems," Johnson said. "Not all of them, but it would solve a lot if you could get off the field on third down."
    The Yellow Jackets (5-4, 2-4 Atlantic Coast Conference) rank last in the league with only eight sacks. Defensive tackle Patrick Gamble leads the unit with three sacks.
    Georgia Tech has tried to bolster its normal four-man pass rush by sending five or more players on blitzes. That tactic opens the way for experienced quarterbacks such as Virginia Tech's Jerod Evans to counter with quick passes to beat linebackers or defensive backs left in man coverages.
    Johnson, who runs the spread option offense, said he offers advice on defense but won't "micromanage" on that side of the ball.
    "I've got enough confidence in our guys on defense to try to let them coach," he said.
    Virginia Tech is averaging 34.9 points and 444.4 yards per game. The Hokies (7-2, 5-1 ACC) are 4-0 this season when scoring 30 or more points.
    NOTES: Johnson said on his weekly radio show Monday night he expects QB Justin Thomas (upper body injury) to play this week. Thomas missed the fourth quarter of last week's game with the injury. Center Freddie Burden missed the second half, also with an upper body injury. Johnson said Tuesday no injury update would be provided to r