Injuries at safety, and even inside linebacker, have Packers players taking the next-man-up mentality. You know, the you-never-know-when-your-number-is-going-to-be-called-so-you-better-be-ready-and-take-advantage mentality.

"We've got me, Pep, Bush, next man up, whoever's in," said safety Derrick Martin. "And at linebacker, same thing. Whoever's in, we feel like they're going to be able to make the plays that keep us on the right page."

It was Martin who filled in for starting safety Morgan Burnett this past Sunday when the rookie went down with an injury against the Detroit Lions.

Martin acquitted himself well even though he was in bracket coverage with Charles Woodson when giving up a touchdown pass to 6-4 star receiver Calvin Johnson.

Now the Packers face a shortage at safety after learning Burnett would be lost for the season on Monday. And Martin is the only true safety 100% healthy.

Nick Collins did not participate during Wednesday's practice with a knee that's bothering him dating back to the Chicago Bears game. Collins had to left that game briefly but returned.

Bearing in mind that Collins returned to the Bears game and also played this past week against the Lions and showed few if any ill effects, chances appear good that Collins will be able to play this Sunday against the Washington Redskins even if he continues to battle to a knee injury, which he admits the pain isn't bad.

"I can sit here and tell you I'm going to be ready every Sunday, but it's not up to me. It's up to the doctors," said Collins. "I'm just doing all the things I need to do to get right for Sunday, go through the testing. However you want to put it, hopefully I'll be out there Sunday."

Preparing to replace Burnett, or even Collins in the event he has a setback, is veteran safety Charlie Peprah who's been in this situation before.

Peprah made his first and only career start against the Atlanta Falcons in 2008 in place of an injured Atari Bigby, and odds are he'll be making his second career start at Washington this weekend. He is now listed first on the Packers' official website.

"That's the sport," said Peprah. "People go down, the next person's got to step up and pull their weight, no drop off. That's why they brought me back, and that's what I'm here for."

Peprah wishes his opportunity to start didn't have to come at the expense of season-ending injury to Burnett, but also realizes he can't pick and choose the occasion where he needs to fill in for a teammate.

"We got a goal that we want to accomplish, and I don't want to be the reason we don't accomplish that goal," said Peprah. "I want to be able to be plugged right in and pick up right where we left off."

Unfortunately for the Packers, Peprah is also dealing with an injury while not serious, could hamper the team's ability to prepare for their opponent.

The fifth-year safety was classified as a full participant in today's practice, but he did sit out the past two weeks with a quad strain originally injured Week 2 against Buffalo and then tweaked during practice the following week when preparing for the Bears.

Peprah said he doesn't like to project when he'll be ready in case he happens to regress, but he also indicated he's "really close" to returning.

Even so, head coach Mike McCarthy is preparing for all eventualities.

We’re working a couple of different combinations. We have

When asked to assess the team's options at the position, head coach Mike McCarthy said, "Charlie Peprah, hopefully he’ll be able to get back, and Derrick Martin and potentially Jarrett Bush, who has spent time back there."

Bush has been practicing primarily as a cornerback since last season and even served as the team's nickel cornerback in Week 4 against the Lions but may have to spend a majority of time preparing at safety because of the injury situation.

It would help matters if rookie cornerback Sam Shields recovers from his own injury woes  and is able to resume his duties as the nickel cornerback to allow Bush to concentrate on safety.

Shields won the nickel cornerback coming out of training camp, but strained his calf in practice last week and didn't play in the Lions game.