Green Bay's pass defense in 2011 was statistically the worst in league history. Encumbered by a defensive line that couldn’t rush a parking meter, much less an NFL quarterback, the Packers upgraded personnel in the offseason to generate more pressure. So far in camp, the additions have added vigor. Free agents Anthony Hargrove and Daniel Muir are nonstop noise machines with spirit, out to prove they still belong in the NFL. And exuberant rookies Jerel Worthy (second round) and Mike Daniels (fourth round) have brought talent and promise to the line, which is suddenly a deep and highly competitive unit.

But heading into Green Bay’s preseason opener Thursday at San Diego, the concern has shifted across the line of scrimmage to the offense. Injuries at left tackle have left QB Aaron Rodgers staring at journeyman Herb Taylor as his blindside protector, and unremarkable practice performances by many of the undrafted and unknown backups has Packer Nation suddenly concerned about the offensive line.

Questions to be answered in exhibition season:

1. Is there enough depth on the offensive line? LT Marshall Newhouse suffered a concussion in practice early in the week and won’t play Thursday against the Chargers. With 2011 first-round pick Derek Sherrod still recovering from the broken leg he suffered last season, that leaves Taylor and underwhelming seventh-round rookie Andrew Datko to man the blind-side spot for now. Newhouse should return soon, but his early injury is a reminder of just how fragile the line is. Behind the starting five, which make for a formidable unit, only Taylor and G/C Evan Dietrich-Smith have any real experience at the pro level. “We have a young offensive line,” coach Mike McCarthy said. “We're trying to get as many guys ready to play as we can. Injuries are part of the game. The next man has to step up, go out there and play. If somebody goes down, that's what we'll have to do." Last regular season, the Packers’ starting offensive linemen missed a combined 17 games due to injury. As the roster is constructed right now, the team doesn’t appear to have the depth to deal with multiple, concurrent injuries, especially at the interior positions.

2. Can the defensive line please wait? Patience is a virtue -- though not one often embraced in football -- and Green Bay’s restless defensive linemen have yet to cultivate it. Pre-snap penalties have been rampant in camp. McCarthy said last week he counted seven during the team’s Family Night intrasquad scrimmage, a day after making a big deal of the problem at practice when 14 were committed. Many of the whistles have been blown on the defense, often for offsides. Most quarterbacks don’t have the compelling hard count of Aaron Rodgers, whose cadence calls are notoriously convincing, but nonetheless McCarthy has said the mental errors are “unacceptable.” The rookie Worthy is especially jumpy and has been flagged multiple times. “At this level, penalties only get you put on the sidelines,” Worthy said after Family Night. “From day one, Aaron's been trying to get me with a hard count. And he got me.” This defense isn’t good enough to be giving away free yards with penalties, and the more disciplined players -- like veteran DE C.J. Wilson, who’s been starting -- will probably play.

3. How much should we expect from Perry? Rookie OLB Nick Perry was drafted in the first round to provide the explosive, effective edge rush the Packers lacked opposite Clay Matthews last year. Perry’s had a relatively quiet camp -- not too many highs, not too many lows -- but in the Family Night scrimmage last week he displayed a bit of the power and speed Green Bay drafted him to deliver. Granted, it was against bottom-shelf OL competition, but it was enough to give Perry some confidence and positive momentum to build upon as he continues to transform from a college DE to a professional OLB. Perry has called learning the new position “an overload” and said the most difficult adjustment is learning to drop into coverage. There are high expectations for him and a lot riding on his ability to grasp the system. Last year, Matthews had just six sacks, nearly half as many as he’d averaged his first two seasons, so he, too, is counting on Perry to draw some attention.

4. Who is the No. 2 cornerback? Charles Woodson is now a safety in the 3-4 base defense and moves to the slot CB spot in the Packers’ oft-used nickel package. Opposite starter Tramon Williams, a 2010 Pro Bowler who had a disappointing season last year, the second job is up for grabs. That was evident the first day of camp, when veteran special-teams ace Jarrett Bush was the other outside corner over incumbent Sam Shields, who had a regressive 2011 season. Since then, second-year standout Davon House has taken many of the snaps with the No. 1 defense, as Bush and Shields have also gotten their chances. Don’t discount rookie second-rounder Casey Hayward, a ball hawk with good play-making instincts. The tackling in the secondary was atrocious last year, so expect the ultimate winner of the No. 2 CB job to be a guy who’s demonstrated some willingness to hit.

For the latest on the Packers, follow updates from James Carlton @CBSSportsNFLGB and @jimmycarlton88.