This season, the Giants lacked their signature pass rush, which had lifted them over the Patriots in Super Bowls twice and had set the tone for the rest of their defense.

Whether it’s via free agency, the draft or trades, the Giants need to upgrade their pass rush, which will allow their linebackers to focus more on stopping the revent and their defensive backs on generating turnovers.

The heart and soul of the Giants D: the defensive line. Let’s begin there.

D-Line: The Giants finished the regular season ranked 22nd in the league with 33 sacks. Jason Pierre-Paul led the way with 6.5 sacks, with Osi Umenyiora second with 6.

It’s almost set in stone that Umenyiora will not be a New York Giant when the 2013 begins, leaving the question of whether the Giants will allow Justin Tuck to remain a full-time starter at left defensive end?

Tuck has been a valuable weapon because he can line up at numerous positions along the defensive line. Now, there is doubt.

Tuck is also on the hot seat a bit. Two years removed from a 11.5-sack year, Tuck’s total has decreased each of the last two seasons. It’s been four years since Tuck notched back-to-back double-digit sack numbers.

Tuck, set to turn 30, is a free agent after the ’13 season.

If the organization wants to retain him but look for a stronger pass-rusher, Cliff Avril, Israel Idonije and Dwight Freeney are the best ends available.

Avril, franchise tagged by Detroit last off-season, had 9.5 sacks in 2012. He’s totaled 29 sacks in the last three years.

Idonije, 32, is a more financially viable option. He’s registered 20.5 sacks over the last three years.

Freeney, the longtime Colt, may seek a uniform change if he wants to return to the defensive end position. Freeney had 5 sacks this season, the second season in which he’s failed to register double-digit sacks. His numbers have declined every year since 2009.

Also set to his the market is Rocky Bernard.

The Giants may look to re-sign the veteran tackle, or stay in-house and look to Marvin Austin to win the spot as he enters his third season.

Linebackers: The biggest revamp likely is going to occur within the linebacking corps.

Of Chase Blackburn, Michael Boley and Keith Rivers, only Boley is probably not on the hot seat.

Rivers, a free agent, has likely run his course in New York.

Blackburn’s volume of effort is admirable, but his athleticism is not up to par for the NFL of today. Rivers, who has battled injuries throughout his time in New York, is a medical question mark.

Some draft prognosticators have projected Notre Dame’s Manti Te’o to fall in the Giants’ lap at No. 19. Te’o, an athletic run-defender and abnormally superior pass-defender, would immediately boost the Giants’ linebacker corps.

Other top linebackers in the draft include George’s Alec Ogletree, LSU’s Kevin Minter and UNC’s Kevin Reddick, all of whom are ranked in the top four at the position, according to ESPN Scout’s Inc.

There is the possibility the Giants go the in-house route, subbing Mark Herzlich at the middle backer spot. I’m not sure, however, he’s ready to be a full-time starter in this league.

Should they check in on free agency, Rey Maulaluga, Brian Urlacher, Danielle Ellerbe and Tim Dobbins are among the best options.

Maulaluga is the heart and soul of Cincy’s defense; perhaps he could provide a similar boost to New York’s.

Urlacher is not the same defender as he was in 2006, but he’s a veteran. I am unsure he’d leave Chicago, but with a new coaching staff coming in, you just don’t know.

Ellerbe filled in for Ray Lewis admirably. He’s a young, athletic option, but has previously stated he wants to remain in Baltimore.

Dobbins was injured filling in for the injured Brian Cushing. He’ll command less money in free agency, though he’s certainly not a game-changer the Giants need.

Secondary:

While much of the attention this off-season will be focused on regenerating the pass rush and adding athleticism to the linebacking corps, most of the decision-making will have to occur in the secondary.

An injury-plagued defensive backfield allowed 10 plays of 40-or-more plays this year, which along with Oakland, Detroit and Atlanta, was tied for eighth-most in the NFL.

Strong safeties Kenny Phillip and Stevie Brown are free agents, and top cornerback Corey Webster hard a target on his back all season long. He’s a candidate for release, as his contract expires after the ’13 season.

The Giants have given no indications of whether they’ll choose to retain Phillips, Brown or both. Phillips will likely command more money on the market, even though he’s coming off an injury-plagued 2012.

Brown, who emerged in his absence, led the Giants and finished tied for second in the NFL with 8 interceptions.

If feasible, retaining both safeties gives the Giants an exotic look on defense, which Brown and Phillips in center field and fellow safety Antrel Rolle shielding the run closer to the line of scrimmage. It was success against Green Bay, when all three safeties were in the lineup.

Obviously, if financial doings work out, keeping both would be ideal for the organization. If not, the Giants may choose to keep Brown, who like Victor Cruz did this season, will face the question of whether he was a “one-year wonder.” But he should cost the organization fewer dollars.

At corner, there are questions about Webster’s future, with Prince Amukamara, Jayron Hosley and Justin Tyron set to fill the void.

That, however, is a very young core of secondary players.

The Giants can choose to pay Webster, who is entering the final year of a 6-year/$43.5M deal and is owed $7M plus$250,000 in workout bonuses.

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