The list keeps on growing for the Packers.

Add safety Nick Collins to the Green Bay Packers growing list of injury concerns.

Collins missed Wednesday’s practice with a knee strain and said he’s not optimistic about playing against the Redskins on Sunday, according to Kareem Copeland.

“I’m doing the best I can to get ready for Sunday,” Collins said. “Just trying to strengthen up the knee right now. It’s a little weak. We’re doing all the right things.

“It’s a knee strain. It happens to the best of us. … It’s out of my hands. I’m just doing what they tell me to do. Probably get out there [Thursday] or Friday and test is out.”

The loss of Collins would be another blow to a Packers defense that has already lost safety Morgan Burnett and, reportedly, linebacker Nick Barnett for the season. Cornerback Sam Shields, who has a calf injury, missed last Sunday’s game and Wednesday’s practice, as well.

Redskins quarterback Donovan McNabb has to be licking his chops.

If Collins is unable to go, the Packers would start some combination of Charlie Peprah, Derrick Martin, and Jarrett Bush at the safety positions. If Shields remains out and Bush starts at one of the safety positions, Brandon Underwood and Pat Lee would be moved into the nickel and dime cornerback spots.

However it plays out, the Packers are dangerously thin in the defensive backfield and will likely have to make a move to add a player.