Virginia Tech’s defense entered the 2012 season making bold proclamations. Cornerback Antone Exum told reporters the unit had the talent “to be the best defense that’s ever been through here.” Behind closed doors, defensive coordinator Bud Foster laid out lofty goals to his team, such as allowing just 13 touchdowns, one fewer than defending national champion Alabama gave up a year ago.

But those goals quickly went out the window, and it played a significant role in Virginia Tech’s worst season in 20 years. The Hokies allowed their 14th touchdown of the season in the second quarter of an Oct. 6 loss to North Carolina, their third defeat in four games at the time.

It was fitting that the distinction came and went during a game in which Virginia Tech gave up more points (48) than it ever had in ACC play. In those three losses, the Hokies allowed an average of nearly 522 total yards to Pittsburgh, Cincinnati and North Carolina. That, though, proved to be a turning point for the Hokies, and they held every opponent under 400 yards the rest of the season.

On the field, Foster credits the improvements to an embrace of the fundamentals, with an emphasis on better tackling and mitigating the big play down the stretch. But even though Foster recently called big plays Virginia Tech’s “nemesis” this year, the Hokies actually allowed fewer plays of 20 or more yards this year (49) when it finished 24th in the country in total defense than it did a year ago (60) with the 10th-best defense in the country. Foster’s unit was also a bit stingier on third down compared to last season.

So what went wrong, other than the fact that Virginia Tech’s offense wasn’t good enough to hide any of the defense’s shortcomings?

Well, after shuffling the secondary in the offseason – Exum moved from safety to cornerback and cornerbacks Kyshoen Jarrett and Detrick Bonner moved to safety — Virginia Tech’s defensive backs struggled to get their bearings early on. It didn’t help that junior Kyle Fuller battled several nagging injuries and the Hokies once again struggled to find a consistent whip linebacker, which forced Foster to use inexperienced defensive backs such as redshirt freshman Michael Cole and freshman Donaldven Manning in his nickel package.

Virginia Tech’s pass rush, which returned a national-best 40 sacks from a year ago, also got off to a slow start, mustering just eight sacks through six games. They had 24 over the final six contests of the season.

“Obviously, you hate to have growing pains, but we did, especially on the perimeter. And that was the discouraging part of the season, because I thought we could have stepped in,” Foster said. “You always kind of feel like you can plug people in and you can be able to keep going, but obviously that doesn’t work the way you want it to.”

But Foster believes the issues in the defensive backfield early on will prove beneficial next season, and it was clear down the stretch that the Hokies developed a rapport back there, even as Foster increasingly dialed up blitz packages and left them on an island. In defeat, Virginia Tech still held Clemson and Florida State to season-lows in yardage.

Redshirt junior Antone Exum emerged as the team’s top cornerback, finishing the season with an ACC-high 15 pass break-ups and earning second team all-ACC honors. Jarrett also had an encouraging campaign in the starting lineup, showing off the versatility to cover wide receivers and help out in run defense. He had 77 tackles this season, second-most behind linebacker Jack Tyler.

If Exum and defensive end James Gayle return for their senior seasons — both have filed paperwork with the NFL draft advisory board — the Hokies would have nine starters back in 2012. There could be a leadership void since Foster credits senior linebacker Bruce Taylor with guiding the turnaround that ultimately salvaged Virginia Tech’s 20-year bowl streak, but he will likely be replaced by redshirt junior Tariq Edwards, an experienced piece who was limited this season by injury.

“I think the big part is we came together,” Tyler said of the defense’s improvement. “Coach Foster wanted us to come together and tell each other, ‘This isn’t who we are. This isn’t good enough. This isn’t Tech defense.’ I thought that kind of brought everyone closer. … When everyone is — Coach Foster says, ‘working like a swiss watch’ — it’s a lot easier to play defense.”

But perhaps the biggest lesson learned heading into Friday’s Russell Athletic Bowl and beyond is to hold off on the bravado until the season progresses.

“We don’t want to jump to conclusions or anything too early, because we thought that was where it was going this year,” Exum said. “But next year, we definitely have the pieces to be a dominating defense, but this year proved that just because that’s what it looked like on paper, that’s not how it’s going to have to go. You’re going to have to go out there and prove that you’re worth that and prove that you’re that playmaker that’s on paper.”