During the week leading up to his first NFL start at middle linebacker, A.J. Hawk looked rather unfazed by the whole ordeal of switching from his customary weak-side spot to take injured Nick Barnett's place in the middle.

He looked the same way on the field Sunday against the Chicago Bears, and the transition went as smoothly as any of the Packers players or coaches could have hoped.

"I was very pleased with him as far as his comfort and his poise and how he handled the whole situation," linebackers coach and assistant head coach Winston Moss said. "I actually throughout the week leading up to the game, I had a good feeling he was going to play well, but he actually exceeded that. So I'm excited, and I'm very pleased with the way it came out."

To say that Hawk looked like a natural in the middle may be overstating it a bit, but Moss used phrases such as "awfully good" and "extremely comfortable" in describing Hawk's play. After coaches reviewed the film, Hawk was credited with a season-high 12 tackles, and Head Coach Mike McCarthy praised him for his work covering Chicago running back Matt Forte on short pass routes.

Hawk talked all week about how playing linebacker is playing linebacker, no matter where he's lined up, and that's how he felt after the game as well. He also took over wearing the helmet speaker for Barnett, who's having season-ending surgery later this week, and he had no problems relaying the calls from defensive coordinator Bob Sanders to the rest of the huddle. McCarthy said when Chicago went to its no-huddle offense, Hawk made the appropriate calls.

"I felt good," Hawk said after the game. "I felt pretty comfortable in there. I watched a lot of film on Nick actually, watched what he's been doing here for five, six years. That's kind of where I tried to base what I was going to do."

Sanders noted that Hawk's preparation was thorough, leaving him no worries about how Hawk would perform.

"I know how hard he works, I know how hard Winston works in getting him ready, so my concern mainly was hoping to help get our guys in the best position to be successful," Sanders said. "I'm sure there's a couple plays if you ask him that he'd like to have back, but overall he did a nice job.

"He's very instinctive."

Those instincts were what the Packers really liked about Hawk when they drafted him out of Ohio State with the fifth overall pick in 2006, and they certainly came into play with this position switch. Moss noted that playing in the middle might allow Hawk to be more aggressive against the run than when he has more pass coverage responsibilities on the outside.

"When that tight end is releasing all the time and he has to get downfield and cover and play in space, I think he does an adequate job with that," Moss said. "But he is better staying around the box and being aggressive and playing upfield and attacking guys, as opposed to playing off and reacting to a guy."

The other player whose versatility was on display was Brandon Chillar, normally a strong-side linebacker who took Hawk's starting spot on the weak side.

Chillar, signed as a free agent this past offseason from St. Louis, was credited with a more modest six tackles, but he had one eye-catcher, getting Forte for a 4-yard loss after a pass reception.

Hawk and Chillar got to work plenty together as the two linebackers in Sanders' nickel defense on Sunday, which the Packers employed almost exclusively as a counter to Chicago splitting tight end Greg Olsen out wide.

The two seemed to play off each other in the nickel very well. They even switched spots at times, with Chillar moving to the middle on some passing downs and Hawk returning to his outside position. Either way, it was hard to argue with the results, which included just 234 yards and three points for the Bears.

{sportsad300}"We did a good job of communicating and working together," Chillar said. "It's a lot of fun working with the guy, and I'm just going to continue to build a relationship and get better.

"Anything you do over and over, you're going to get better at. We're going to continue to work hard."

Hawk echoed that and by no means thinks the defense reached a peak with its solid performance on Sunday.

"We talked about attention to detail after last week (at Minnesota)," he said. "We didn't do that very well last week, losing leverages on certain things here and there. We wanted to come out and want to be flawless with what we do. We never really are but we're trying to get there. We improved but we still have a long ways to go."

Hawk may not have as far to go as originally thought when it comes to his new position, but with six regular-season games left it will be worth watching to see where his game is at the end of the year.

"The guys that step up, the guys that step in, the guys that move over, the expectation is to play at a high level, and certainly he started out playing at a high level," Sanders said. "That's what it takes for us to be successful, 11 guys playing fast, physical and confident. We have to start that way and we'll be building from there."