Then Perry Fewell's unit was battered by injuries, losing Terrell Thomas, the team's first two draft picks and two more cornerbacks to injuries.
But as the Giants approach the preseason finale at New England on Thursday, they've not only moved on from the various injuries but they feel good about what they've seen from the defensive side thus far.
So even though Tom Coughlin may opt to rest his starters for most, if not all, of the Giants' second game in four nights, the defense feels prepared for the regular season.
"I think we're pretty ready," defensive end Justin Tuck said after the Giants' 17-3 loss to the Jets on Monday night. "Considering the injuries we've had and the guys we've brought in and things of that nature, I feel as though we're flying around, and we showed some great things. Once we get to game-planning a team like we will, watching [the Redskins], for that first game, you'll see us really get a whole lot more comfortable with our schemes, and fly around."
The defense certainly had a drama-filled camp starting with the Umenyiora saga. Fewell had Umenyiora for only three practices due to a contract dispute and a knee injury.
The defense has gotten by with Tuck and Jason Pierre-Paul. But then Fewell lost one of his most dependable players in Thomas, who led the Giants in tackles and interceptions last year and seemed poised for a big season in Fewell's scheme.
The Giants' depleted secondary has been hit hard by injuries with Thomas, Bruce Johnson and Brian Witherspoon all suffering season-ending injuries. And then there's first-round pick Prince Amukamara, who broke his foot in his second practice of the year and is out until perhaps the end of September or early October. Second-round pick Marvin Austin joined him on the sideline with a season-ending torn pectoral injury.
Still, the Giants' defense held the Jets' starters to seven points for just more than a half.
With Thomas out, Fewell has utilized safety Antrel Rolle against the slot receiver on some passing downs with Deon Grant and Kenny Phillips at safety. Rolle saw some action against Santonio Holmes in the slot and the Giants liked what they saw.
"Last year we did a great job of putting different packages out there on the field based on the personnel that we had," cornerback Corey Webster said. "Last year, we had an opportunity to do that with him so this year wasn't that foreign to him. I think he did a great job of covering the receivers and he is a former cornerback so it's not that far out for him. It helped us to change up the coverage last year so I think it would be wonderful and he would have no problem doing it."
Webster and cornerback Aaron Ross will have to elevate their play without Thomas. But mostly, they have to stay healthy.
One positive is that the Giants will get reinforcements in the next month or so when Umenyiora and Amukamara make their way back from surgeries.
That should help them with their ultimate goal, which is to finish strong. The start of the 2011 season may have been rocky thus far but the Giants' defense only cares about the way it finishes after failing to do so late last year against Philadelphia and Green Bay.
"A big emphasis," linebacker Michael Boley said. "That has been our Achilles heel the last two years. We have had that tendency to come out on fire and not be able to sustain that throughout the course of the season.
"As we all saw last season, we had some games where we were hanging in at the end of the game and things fell apart," Boley said. "So that is one thing that we want to get corrected as a whole."