There's no way the Green Bay Packers can really replace Al Harris and Aaron Kampman in their defense, but they're going to go about filling those roles with players who aren't exactly new to the duty being thrust upon them.

Harris and Kampman are out for the remainder of 2009 with knee injuries, and as Head Coach Mike McCarthy announced on Monday, Harris' starting cornerback spot will be taken by Tramon Williams, who also started for Harris for four games last season when he was out with a lacerated spleen.

Williams performed well in Harris' absence last year, intercepting a pass in each of the first three games he was in the starting lineup. He finished the season with a career-high five interceptions.

Williams acknowledged that his job doesn't really change much with Harris out. With the Packers playing so much nickel defense, Williams estimates he's gotten about 70 percent of the snaps already this season. Now that bumps up to closer to 100 percent, but he's done it before.

"I feel comfortable," Williams said. "I don't feel that I have to step in and work some kind of miracle. I just feel like I'll step in and let the game come to me. That's what I think I did last year when he had the spleen injury. I should come in and not feel I have to do anything out of the ordinary. Just play my technique and everything will take care of itself."

Williams also had become the team's primary punt returner this season following injuries to Will Blackmon and Jordy Nelson. With Nelson healthy again, McCarthy said the coaching staff is looking at Williams, Nelson and Charles Woodson as options on punt returns.

The bigger adjustment in the secondary probably comes in the nickel and dime defenses, because the players who will step into those roles will be less experienced in terms of snaps from scrimmage than Williams.

Fourth-year pro and special team standout Jarrett Bush had been the dime back and will likely move up to nickel now, while rookie Brandon Underwood had taken over in the dime when Harris went down last Sunday.

Another option for one of the roles is newly signed cornerback Josh Bell, who started five games for the Denver Broncos last season when Champ Bailey was injured.

Bush is probably the player who will see the biggest change because of how much the Packers have employed the nickel this season. A cornerback earlier in his career, Bush played some safety last year and was there most of the way through training camp before returning to cornerback with the injuries to Blackmon and Pat Lee.

"That's one of the values of having a guy and playing him in different roles, it forces him to have to learn different positions," defensive coordinator Dom Capers said. "When you get to this point in the season, the more guys you have that have multiple position possibilities, the better it is for you. Because if a guy can only play one spot, it gets tough."

As for Kampman's outside linebacker spot, the options are rookie Brad Jones, veteran Brady Poppinga or second-year pro Jeremy Thompson, or any combination thereof.

Jones started in Kampman's place two weeks ago against Dallas when Kampman missed the game with a concussion, and he held up well. Whether or not Jones gets the call again, the coaching staff isn't saying for sure, but the fact that Jones has one start and significant game snaps to build upon is a positive step.

"I'm confident in my ability to play football, but I think with each game, comfort level and knowledge goes up," Jones said. "So I think every game I get a little more comfortable, a little more knowledge."

With that limited experience - Jones hadn't taken any defensive snaps from scrimmage prior to the Dallas game - hopefully comes some reliability. Jones had shown a quick adaptability to special teams and appears to have done the same on defense.

"He's got some of the skill set that we look for in that position, from the standpoint of having the flexibility to drop into coverage, enough physicality to play the run, and some instincts in terms of rushing the passer," Capers said.

"He did a nice job for the first time out. He's still a rookie, still learning, but what you hope is the more reps that he gets the more consistent he becomes. In these games it's important. If you've got 60, 65 plays you've got to be able to perform at a high level every play, because you never know what play is going to make the difference in the game."

{sportsad300}Poppinga also rotated in to take some of Kampman's snaps after he left with the knee injury on Sunday, while Thompson hasn't been much of a factor this season since a series of shoulder/neck stingers sidelined him for a good portion of training camp. But McCarthy said Thompson has been playing on special teams and would be active for this game.

McCarthy expressed confidence that he's seen enough growth in the reserve players that they'll perform well, no matter who gets the bulk of the work. Capers appealed to their pride as professionals, and the desire he'll feel they have to contribute meaningfully.

"You have to challenge the guys that are stepping in," Capers said. "They have a responsibility. If you're going to be out there on the field, you've got a responsibility to the rest of the guys to go out and do your job and be accountable and prove to them you can earn their trust.

"Because that's what this business is all about is can guys count on me to do my job and earn the trust of guys around you, and that's what makes good teams."

A good defense is what the Packers have become lately, and they certainly don't want the injuries to start turning things the other direction.

Following the bye week, at 2-2, the Packers were ranked 18th in the league in total defense, and they've climbed considerably since, all the way up to No. 3 with a 6-4 record. The last time the Packers were ranked this high in the league in total defense in Week 12 or later was 1996, when the team ended the year No. 1 in total defense and in the Super Bowl.

"I think we're playing with more passion," nose tackle Ryan Pickett said. "That's what was missing part of the season I think. We found a way to get that back and we're going to keep it going."

They have to do so with some different parts in key places, but they feel they're ready.

"Our defense is still going to plug along like they have been," Jones said. "Those are two great players. It's not like you have another Aaron Kampman or another Al Harris sitting on the sideline somewhere. But our defense is not going to drop off by any means. Our defense is still to be reckoned with."