Questioning the Packers' nickel

As many of you pointed out, I omitted a critical issue in Monday's post on NFC North positional battles: The Green Bay Packers' nickel spot.

Considering how frequently the Packers use sub packages under coordinator Dom Capers, the nickel back is almost like a 12th starter. That fact requires some pause in light of recent developments, most notably the swift ascent of undrafted rookie Sam Shields to the top of the depth chart.

As we discussed during our training camp tour, Shields displayed surprisingly mature instincts in coverage and looked much more comfortable as a cornerback than he did as a kick and punt returner -- the original role the Packers envisioned for him. But to add some context to the original observation, those instincts merely provided a hint that Shields had a chance to make the team, which in itself is a pretty nice result for a rookie free agent. At that point in camp, I don't think anyone considered him a potential Week 1 nickel back.

Much has changed since then, and now I think it's fair at least to scrutinize the Packers' offseason decision to sit tight from a personnel perspective. If you recall, their plan was to deploy some combination of second-year player Brandon Underwood with three players returning from significant injuries to create depth and competition.

Underwood, however, has been limited by a shoulder injury that dates back to his college career. Veteran Al Harris remains on the physically unable to perform list. Will Blackmon has been unable to shake knee soreness, and Pat Lee's preseason performance has been shaky. That left a void behind starters Charles Woodson and Tramon Williams, one that Shields has been given an opportunity to fill. If he wins the job, the Packers will have two rookies -- Shields and safety Morgan Burnett -- in their five-man nickel package.

Is Shields' opportunity based on merit, or is it because the Packers' options are so limited? I'm guessing that's a question the team didn't think it would face in the final week of the preseason.