Defensive coordinator Dom Capers' instant impact on units that assume his 3-4 scheme has been well-documented throughout his career, and Capers' impact on the Packers' defense in 2009 was undeniable.

Looking at the league rankings over the last two years, the Packers rose from 20th to second in total yards allowed, 26th to first in rushing yards allowed, and 22nd to seventh in points allowed in Capers' first season. The defense also led the league in takeaways.

But Capers doesn't view his rebuilding project as complete by any means, and not just because of the obvious - that the Packers struggled against the spread-out offenses with veteran quarterbacks. There's another area he's taking a good, hard look at that Head Coach Mike McCarthy mentioned briefly in his remarks at the NFL Scouting Combine last week, and that's the "sudden-change defense."

The Packers define sudden-change defense as those times the defense takes the field after a turnover or a long return deep into defensive territory by the opponent. It's an adverse or unexpected situation for which a team really needs the defense to respond and get a quick stop, or limit the offense to just a field goal.

Capers and McCarthy will be the first ones to say the Packers simply weren't good enough with sudden-change situations on defense last season, and improvement there could go a long way toward helping Capers' unit take the next step in its redevelopment.

"I've just always felt that the really outstanding defenses thrive in those situations where you have to go in with your back to the wall," Capers said. "That can be part of our growth process as a defense, where in those situations we can go out and perform better than we did."

The statistics from last year clearly show sudden changes as a weakness. While the Green Bay offense did a commendable job taking care of the ball - turning it over a league- and franchise-low 16 times in the regular season - the defense didn't hold up its end the rare times that did happen.

Taking away one interception that was run back for a touchdown (at Tampa Bay), the Packers allowed the opponent to score nine times off of the other 15 turnovers, and most disturbingly all nine scores were touchdowns.

Add to that the results from long returns and the concern mounts. Looking at the opponents' four longest kickoff returns (at Tampa Bay, vs. Minnesota, vs. San Francisco, vs. Baltimore) and two longest punt returns (both vs. Cincinnati) last season, the defense allowed four touchdowns, one field goal and got one stop - when Tramon Williams intercepted Baltimore quarterback Joe Flacco in the end zone on Monday Night Football (Dec. 7).

It should be noted that the touchdown after Minnesota's long kickoff return - a 77-yarder by Percy Harvin - should have been a field goal, but defensive end Johnny Jolly was flagged for a personal foul after the Packers had stopped the Vikings on third down in the red zone, giving Minnesota a fresh goal-to-go set of downs. And even then the Vikings scored only when Adrian Peterson barely broke the plane on fourth-and-goal from the 1.

But the bottom line is that the defense allowed 13 touchdowns in sudden-change situations last season, more than one-third of the 36 total touchdowns it gave up in the regular season. And the sudden-change struggles were especially costly in the NFC Wild Card playoff, when the offense turned the ball over on two of its first three snaps and Arizona answered with drives of 40 and 22 yards for two quick touchdowns and a 14-0 lead less than six minutes in.

There's no telling how differently that game might have unfolded had it been only 10-0 or 6-0 at that stage instead, but Capers is counting on his defense to find out in 2010 if called upon in similar fashion.

"You're on the road, you're in an emotional setting, and the last thing you want to do is let the home team get the crowd going and get the momentum in the game," Capers said, recalling the playoff game. "It probably started as poorly as it could for us. It gave them great confidence, and it carried on throughout the game.

"So much is being able to go out and set the tone, set the tempo, especially when you're playing on the road."

{sportsad300}So the million-dollar question then is how do the Packers go about improving in this area? First and foremost is working on an aspect that goes hand-in-hand with sudden-change defense, and that's red-zone defense.

The Packers allowed opponents to score touchdowns 61 percent of the time they got inside the Green Bay 20-yard line (28-of-46), a figure that ranked 28th in the league. That was the only major defensive category in which the Packers weren't ranked in the top 10 last season. All teams have different packages and wrinkles in their defense for the red zone, and it's up to the Packers to find ways to be more effective.

In addition, following McCarthy's mantra of getting what is emphasized, Capers plans to create more practice situations in which the defense is thrown onto the field in a sudden-change scenario and has to react and perform.

"We will do that, to where we're going to put the guys out there and make them start with their backs against the wall at the short end of the field," he said. "We have to point out to them that no matter where they are, we have to keep them from getting into the end zone.

"We were seventh in the league in scoring defense, and to move into one of top two or three scoring defense teams, the red area and the sudden change will be a big part of that."

Capers believes it will take the right combination of attitude, experience and leadership, and he's confident another year in the scheme will help the Packers develop all of that.

He's seen what it takes with his 1999 Jacksonville defense that allowed the fewest points in the league, and his 1994 Pittsburgh unit that was No. 2 in scoring defense. In the sudden-change spots, they didn't panic or fret, but rose up and played their best.

"We had real veteran, mature teams, and you've got to have your veteran leaders step up in those situations, look everybody in the eye and say, 'Hey guys, this is our chance. This is our chance to show how good we are. Now let's go out and do it,'" Capers said. "It's about being a mature competitor, the confidence throughout what you're doing, and the ability to go out and do it.

"To me that's the next step. We have to play the same way, with the same attitude, no matter if the team has 80 yards to take the ball or if they've got the ball down inside of our 5-yard line. We have to find a way to go out and get off the field, or keep them kicking field goals. That's part of the process you go through in terms of developing into a real dominant defense."