New York Giants DE Mathias Kiwanuka is back to playing what he calls his "natural position."  (US Presswire)

If the Giants' defenders looked more comfortable during Sunday’s 38-10 win over the Green Bay Packers, it’s because they were.

The return of S Kenny Phillips (sprained MCL) allowed the defense to return to the three-safety formation that defensive coordinator Perry Fewell has used during the Giants’ Super Bowl run last year.

What’s more, the shift allowed SLB/DE/DT Mathias Kiwanuka to move back down to the defensive line, where he’s admittedly more comfortable.

“I’ve said all along that defensive end is my natural position,” said Kiwanuka, who had two sacks and three quarterback hits against the Packers while playing exclusively along the defensive line.

Kiwanuka has spent most of his NFL career shifting between linebacker and defensive end, with some brief moments at defensive tackle sprinkled in. He played end at Boston College, but has moved back and forth between positions in New York because of a variety of circumstances that include depth issues at strongside linebacker and DE Osi Umenyiora’s season-ending knee surgery in 2008.

He seemed poised to stay at defensive end in 2010 when he began the year with four sacks in three games, but a herniated disc in his neck ended Kiwanuka’s season prematurely. The Giants signed him to a low-risk, two-year deal coming out of the lockout and Kiwanuka found himself back at strongside linebacker to start the 2011 season.

Obviously everything worked out fine for the Giants and Kiwanuka as the former won the Super Bowl and the latter received a contract extension through the 2015 season. But before Kiwanuka inked his new deal, coach Tom Coughlin and general manager Jerry Reese held a meeting to let Kiwanuka know that his role was going to continue to change every week, depending on the team’s needs at linebacker and along the defensive line.

So even though Kiwanuka insisted defensive end was his natural position, he readily admitted, “This is what I signed up for.”

But promises aside, Kiwanuka is best at defensive end because it takes a lot of coverage responsibilities off his plate.

“It’s easier to prepare for one spot,” he said. “When I got to go back and forth, there’s a lot more preparation for it.

“One meeting room, one line for drills, that’s pretty simple,” he added.

That’s why the return of the three-safety formation is so promising for Kiwanuka, and by extension, the entire defense.

The look utilizes linebackers Chase Blackburn and Michael Boley -- who have more experience at the position than anyone else on the team -- so Kiwanuka can focus on pressuring the quarterback and stopping the run, as well as giving a breather to defensive lineman like Jason Pierre-Paul, Justin Tuck, Umenyiora and Chris Canty.

The formation seemed to fit the Giants on Sunday, as reigning MVP QB Aaron Rodgers was sacked five times and tossed an interception.

Phillips -- who aggravated his knee in the fourth quarter, but told ESPN radio that he would be able to play Monday against the Redskins -- S Antrel Rolle and S Stevie Brown combined to make 12 tackles, but they also gave Fewell more flexibility, which has been the key to the personnel package from its inception in 2010.

“Their coverage skills are better and they can also come down and support the run,” Kiwanuka said of the three safeties.

The Giants did use the three-safety look a bit prior to their Week 12 win, but Phillips’ return (he had been out since Week 4) allowed Fewell to go “full-bore” with it, to use his words.  

Even when Phillips left Sunday’s game in the fourth, S Tyler Sash stepped in and the formation remained intact.

“Obviously they’re great players,” said Redskins coach Mike Shanahan, who didn’t see the formation in the Giants’ Week 7 win over his team but likely will when they meet Monday night. “You’ve got to really execute because they’re safeties, but they have the ability of corners. Usually you don’t find those types of athletes; guys that can defend the pass and do the run at the same time ... one of the reasons they were Super Bowl champs.”

Of course, the formation looks a bit different than it did the last two years.

It was born out of necessity, as the Giants were thinner at linebacker than they were in the secondary (that circumstance remains the same as linebackers Keith Rivers and Jacquian Williams continue to battle injuries), but it flourished because of Rolle and veteran Deon Grant’s ability to play closer to the line. Grant is no longer around, but Brown has earned a starting roll, thanks to his five interceptions this season.

On Sunday, the formation dictated that Rolle play nickelback, which is something he’s expressed objection to in the past. But just as Kiwanuka was willing to play linebacker, Rolle sacrificed his natural safety position in order to make the defense better.

“Nickel is something that I’m used to playing, it’s something I’ve played my whole career,” he said Monday. “It’s kind of a natural fit. Although I love playing safety, one thing I like more than playing safety is winning games.”

Rolle was a major reason that Packers WR Randall Cobb -- who had seven touchdowns over his previous seven games -- was limited to four receptions and 39 yards on seven targets Sunday. 

It's an easier leap for Rolle to make this season. The last time he bought into playing the nickelback roll, the Giants held six consecutive opponents to 20 points or less and pocketed the franchise’s fourth Super Bowl title along the way.

So for Rolle and the rest of the defense, winning makes it all the easier to buy into the scheme.

“I think we had a lot of fun out there playing the game [Sunday] and we beat a very, very good opponent,” Rolle said.

Follow the Giants and Alex Raskin @CBSGiants and@AlexRaskinNYC.