GREEN BAY, Wis. -- Mike Neal's comfort level at his new position is being quickly put to the test by the Packers.

Green Bay drafted him in 2010 as a defensive lineman. This year, he transitioned to outside linebacker. Now he'll need to assume even more responsibility with four-time Pro Bowler Clay Matthews expected to miss at least a couple weeks with a broken right thumb.

Pressure? Only if it's in reference to rushing the quarterback. Neal is coming off what he termed the best game of his career after six tackles and a sack against Detroit last week.

"Nothing really," Neal said Wednesday when asked how much Matthews' absence would change the defense. "We're going to miss Clay. Clay brings a lot of stuff to the table ... We're not going to be able to mimic what Clay (does) but we can control what we do, and as long as we do that, we'll be fine."

Once again, the Packers will be experiencing life without their best defensive player. Matthews hurt his thumb while sacking Matthew Stafford on the last play of the third quarter in the 22-9 win over the Lions.

Asked about Matthews' possible return, coach Mike McCarthy said it might be "multiple weeks ... I think any time you're dealing with the wrist and thumb area every injury is specific to that particular injury and his is no different. It's going to take a couple weeks at least."

Matthews wasn't the only casualty in the linebacking corps. Like Matthews, inside linebacker Brad Jones will sit out this week's game in Baltimore against the Ravens with a hamstring injury. McCarthy said he doesn't think Jones will be out for long, and that he would be re-evaluated next week.

Jones' replacement, Robert Francois, suffered a season-ending Achilles injury in the Lions game. On Wednesday, backup outside linebacker Andy Mulumba missed practice with a sore ankle, though McCarthy said he's hopeful he can go Thursday.

The Packers also have A.J. Hawk, Jamari Lattimore and Sam Barrington on the inside, along with Nick Perry and Nate Palmer on the outside.

McCarthy is fine with the depth at the position.

He must be comfortable if Green Bay called up cornerback James Nixon from the practice squad to take Francois' spot on the roster. On Tuesday, the Packers signed undrafted free agent rookie cornerback Jumal Rolle to the practice squad. Rolle has also spent time with the Bills and Saints.

As of now, it appears as if Neal and Perry will start on the outside against Baltimore, with the steady veteran Hawk inside and Lattimore inside.

As much as they don't like playing without Matthews, the Packers do have experience going without him. Matthews missed four games last season with a hamstring injury. He was also sidelined for a game in 2010, and training camp in his rookie year of 2009 with a sore hamstring -- though Matthews did play all 16 games in that rookie season.

Matthews also left the 34-30 loss to the Bengals two weeks with a hamstring injury. He has three sacks and two forced fumbles this year.

Matthews, whenever he returns, will likely need a cast.

Besides rushing the quarterback, Neal is still picking things up about his new position, especially with coverage.

The Packers hope that carries over to Sunday.

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