Packers' defensive depth about to be tested with game against Rams in St. Louis

GREEN BAY, Wis. – The Green Bay Packers are about to find out if their defense truly is deeper than it was last season.

The Packers ranked dead last in the NFL in yards allowed in 2011, prompting general manager Ted Thompson to use his first six draft picks on defensive players and add two more rookie defenders via free agency.

Some of those rookies, along with several holdovers whose defensive roles have been limited to this point, will likely see action Sunday against the St. Louis Rams at the Edward Jones Dome.

The Packers will be without four starters on defense: inside linebacker D.J. Smith, who was placed on injured reserve this week with a knee injury; outside linebacker and rookie first-round pick Nick Perry (knee); cornerback Sam Shields (shin/ankle); and defensive tackle B.J. Raji (ankle).

Smith, Perry and Shields were injured last Sunday at Houston, while Raji missed that game with the ankle injury he suffered at Indianapolis on Oct. 7.

Fourth-year veteran Brad Jones took over after Smith went down against the Texans and is the logical pick to start.

At outside linebacker, veteran Erik Walden, who had been splitting time with Perry, figures to play the entire game with undrafted rookie free agent Dezman Moses possibly in the mix, too. Long term, Frank Zombo has returned to practice from the physically unable to perform list, and while he won't play this week, he'll also provide depth once the team adds him to the 53-man roster.

At cornerback, rookie Casey Hayward, who had two interceptions against Houston, is on course to start. Davon House, who had been working with the starters before an Aug. 9 shoulder injury, should also be back. Jarrett Bush, who started training camp as a starter, is also an option.

And without Raji, who made his first Pro Bowl last year, the Packers managed to bottle up running back Arian Foster (17 carries, 29 yards) with strong efforts from veteran defensive tackle Ryan Pickett and defensive ends C.J. Wilson, Jerel Worthy and Mike Neal. Rookie Mike Daniels also saw action.

"It's one of the real keys in this business: You have to have depth," defensive coordinator Dom Capers said. "That's why you tell these young guys, 'You never know when you're chance is going to come, but you need to be ready when it does come.' With the number of young guys we've played to this point in time, you've seen some of those guys get better."

That's especially been the case with Hayward, who has three interceptions in the past two games and has shown remarkable growth.

"He's a smart kid, but he's really picking up the finer points of the defense," cornerbacks coach Joe Whitt said Friday. "A lot of guys who are rookies are just running the playbook, what's in the playbook. They're not actually playing football. And this guy's playing football. He hasn't really made a lot of mistakes. He's a mature young man. He doesn't act like a rookie."

While Smith wasn't perfect in the first six games, he managed the game as the defensive signal caller — A.J. Hawk will now wear the radio transmitter helmet with Smith out — and his loss leaves the Packers thin. Hawk seems like the obvious choice there, although he's had a renaissance season in part because he hasn't had to spend as much time in coverage.

"I think we have to take a look at these guys and see where they are. They're all capable of handling certain facets of the game," Capers said. "We're playing a lot of different personnel groups and sometimes it's good to have guys who are specialists in their personnel group."

Notes: Packers coach Mike McCarthy said WR Greg Jennings, who has been nagged by a groin injury suffered in the Sept. 9 opener, will miss his third consecutive game because of it. . McCarthy said RB Johnny White, claimed on waivers from Buffalo, "had a very good week of practice. You can see his experience in special teams. We've been very, very impressed just with the way he has picked things up."