EAST RUTHERFORD, N.J. — There was a drumline before the Giants practiced on July 28, and afterward, everyone from quarterback Eli Manning to general manager Jerry Reese signed autographs for the 7,500 fans who lined the perimeter of their practice fields.

But make no mistake, this is not a time of celebration for the Giants. Not like last year, when they entered the new season as defending champs. Even though this team has won two Super Bowls in the past six seasons, Reese put the entire organization “on notice” when he addressed the media on the first day of camp. “We want to do better and we will do better,” he said.

After starting out 6-2, the Giants finished 9-7 and failed to reach the postseason in 2012 for the third time in four seasons—and they’re still trying to fill the void of missing pieces nearly six months before their stadium hosts Super Bowl XLVIII. They can start getting better by reclaiming a defensive identity.

“Believe me, I know,” says defensive end Justin Tuck, who has been the captain of his unit since 2010. “That’s our focus. It has to be. And we’re kind of putting it right there in front of our faces.”

Tuck and his defensive teammates understand the correlation: Both times the Giants won rings, they had an unmistakable identity on defense. When they missed the playoffs, they didn’t. So while this team lives by a “talk is cheap, play the game” mantra under coach Tom Coughlin, the defense has started its 2013 campaign by talking through everything that needs to be done.

The word of choice, Tuck says, is “dominant.” Players and coaches constantly say it in meetings and on the practice fields. Safety Antrel Rolle has been the most vocal. Defensive end Mathias Kiwanuka has polished the talking point: “Instead of waiting until it’s necessary to try to turn it on, let’s get our identity taken care of right now in camp.”

The turnaround won’t be easy. This is a defense that finished 31st in the league last year, with 6,134 yards allowed. Gone, too, are key pieces of the Giants’ championship defenses—Osi Umenyiora, Chase Blackburn, Michael Boley, Chris Canty and Kenny Phillips. And Jason Pierre-Paul, the unit’s young star, had back surgery in June and remains shelved on the physically unable to perform list.

In the linebacker corps and the secondary, the Giants’ approach has largely been “use what you have.” Now calling the plays in the defensive huddle is Mark Herzlich, the former undrafted free agent who has started a total of four games, and the secondary, which yielded 4,068 passing yards in 2012, has the same starting lineup from the end of last season.

Reese isn't happy having won two Super Bowls in the past six years—not when Big Blue hasn't been to the playoffs in three of the past four seasons. (Julio Cortez/AP)

The onus to carve out an identity falls on the defensive line—the unit powered the Super Bowl XLII and XLVI defenses but often led to the Giants’ frustrations last season. Reese added a few pieces this offseason: a starter in free agency, Cullen Jenkins, and second- and third-round picks Johnathan Hankins and Damontre Moore. But as the Giants learned last season, the definition of a dominant defensive line is constantly changing in the era of new-wave offenses.

“You’ve got to have guys that can play different roles. They’re asking me to do a lot this year that I haven’t done before in my career,” Tuck says. “That’s the way of the world. Offenses have changed, and the pro-style quarterback is few and far between now. There are more athletic quarterbacks, more systems to promote their athleticism, and we have to be the same way.”

Tuck wouldn’t divulge secrets. But he acknowledged that the Giants might mix in some more 3-4 fronts, which are often well-suited to plugging the gaps of read-option offenses. But this is not a scheme overhaul; instead, it’s about being progressive, creative and learning from last season’s foibles.

Looking back at game film, Tuck was “disgusted” upon seeing a proud defense that sometimes “looked like we hadn’t even practiced that week.” Same with Rolle, who cringed as he watched some of the breakdowns and would ask himself, “What the hell happened here?”

In his preseason undressing of the organization, Reese pointed to the Giants’ inconsistency, saying, “At times last year we looked like a good football team, and at times we looked like a bad football team.” Although it was before Colin Kaepernick became the starting quarterback, the Giants held the 49ers to just three points at Candlestick Park. Yet they trailed the Bengals by two touchdowns just four minutes into their game and got blown out 31-13. They were able to stifle Aaron Rodgers and Drew Brees but bled 67 combined points to the Falcons and Ravens when their postseason hopes were on the line.

The Giants’ offense had its own lulls last season, but Manning will always be able to put points on the board; since 2008 New York has ranked in the top 10 in points per game. But if the Giants want to have a chance at playing in their home stadium come Super Bowl Sunday, their defense must, as Coughlin puts it, “represent something.”