EAST RUTHERFORD, N.J. -- Perry Fewell's second season with the New York Giants was supposed to get easier.
With Giants players feeling more comfortable with the defensive coordinator's system, Fewell figured he had a top-five unit at his disposal ready to do bigger things in 2011.
But the preseason was as kind to Fewell as Michael Vick was to the Giants' defense late last year.
Fewell has already lost leading tackler Terrell Thomas, defensive signal-caller Jonathan Goff and several valuable substitutes to season-ending injuries. He had to go through almost all of camp without Osi Umenyiora and first-round pick Prince Amukamara and may not have them back for a few more weeks.
The injuries have forced Fewell to tinker weekly with a defense he thought had big-time potential at full strength. But he says he hasn't had to drastically alter his scheme.
"If I had all those guys, we think that we could have been a really, really great defense," Fewell said. "But I still think we can be a good defense."
Fewell will get a preview of what he has on defense Sunday when the Giants open against Washington with a rookie middle linebacker at the helm and a thin secondary.
On top of that, Justin Tuck, the heart and soul of Big Blue's D, is concerned about lingering pain in his neck from a stinger suffered against the Jets in the third preseason game.
No one would blame Fewell if the defensive mad scientist just went plain mad from all the injuries this preseason. But Fewell and the Giants are confident they still have plenty to work with on a unit that ranked first or second in total defense for 10 consecutive weeks last season.
"Our expectations haven't changed," Tuck said. "We still feel very confident in our scheme and the players we will put out there on Sunday. Everybody knows that if this one position goes down, there's always one guy right behind. So we probably simplify the defense a little bit but for the most part we go about business as usual."
The first order of business for Fewell this week was to get rookie middle linebacker Greg Jones up to speed with the first team. Goff tore his ACL in practice Monday but the severity of the injury wasn't known until Tuesday.
"We lost leadership and we lost command with Jonathan and obviously know-how," Fewell said. "Jonathan was an extension of us as a coaching staff because he could communicate what we wanted. We just put that on some of the other guys, so no, we are not going to limit ourselves."
The Giants released second-team middle linebacker Phillip Dillard in final cuts last Saturday and promoted Jones, who had impressed as the third-team middle linebacker in camp. Now Jones, a two-time All-America linebacker at Michigan State, is slated to start the first game of his pro career.
"He is a little nervous," Fewell said. "We like him for the future but the future is now. We have a lot of confidence in him."
Jones' strength is playing against the run, so Fewell could go with three safeties during passing situations. And to help simplify things for Jones, Fewell could have outside linebacker Michael Boley relay some of his calls to the huddle.
Safety Antrel Rolle could also have more responsibilities. Last year, the Giants had the safety playing down low against the run and blitzing on occasion while also moving him back in coverage at times.
This preseason, the Giants used Rolle against slot receivers after they lost Thomas for the season.
"There are more responsibilities but we got to help out the young guys who have never been here before," Rolle said. "But at the same time I'm a year older in the system and I understand things better."
Fewell has other players returning for their second season in his system. He has linebacker Mathias Kiwanuka after losing him for all but three games last year.
And second-year players Jason Pierre-Paul and Linval Joseph are ready for bigger roles. Last year's first- and second-round picks will start in the season opener, Pierre-Paul at defensive end for Umenyiora and Joseph at tackle in place of the departed Barry Cofield.
But Fewell concedes that it could be a few more weeks until he gets a feel for his younger players. Of the 10 rookies on the roster, six are on defense, including four linebackers.
"That has been the real challenge," Fewell said. "I am learning Greg and Jacquian [Williams] now. It may take me a couple weeks or a couple games before I know them. That is the maturation that is taking place right now."
It was supposed to be easier for Fewell and the Giants' defense in their second year together. So far, the start to 2011 has been painful.
But what matters most to the Giants is how they finish after losing to Philadelphia and Green Bay with a playoff berth on the line last season.
"I don't know if you get those kinds of games out of your system, but you move on," Fewell said.
"Some guys have to assume some different roles and we are doing a good job of trying to fit those pieces into place," Fewell said. "Now, how fast those pieces will develop for us, we will find out on Sunday."