Chicago Bears

Key additions: Running back Michael Bush, linebacker/special teams Blake Costanzo, quarterback Jason Campbell, receiver Brandon Marshall (trade), receiver Devin Thomas, receiver/returner Eric Weems.

Key losses: Running back Marion Barber (retired), cornerback Zack Bowman, cornerback Corey Graham.

Come on back: Lost in the shuffle of the Marshall trade were the return of three free agents who should play key roles in 2012. Tight end Kellen Davis figures to get an expanded role in offensive coordinator Mike Tice's scheme, especially as a receiver. Cornerback Tim Jennings should retain his starting role opposite Charles Tillman, with D.J. Moore in the nickel. And safety Craig Steltz will provide reliable depth at safety and will be one of the Bears' special teams leaders after the departure of Graham and Bowman.

What's next: There is no urgency yet, but the Bears will need to make peace with tailback Matt Forte at some point before the summer. Forte isn't happy that he's been made the Bears' franchise player and briefly lost his public composure when Bush signed a deal that guaranteed him about the same amount of money as the franchise tag will pay Forte. It's not a big deal if Forte skips the Bears' offseason program or even misses a few days of training camp, but the Bears will want to find a way to eliminate this issue by early August. Meanwhile, it wouldn't be surprising if the Bears address their offensive line during the draft.

Detroit Lions

Key additions: Defensive end Everette Brown, cornerback Jacob Lacey.

Key losses: Cornerback Eric Wright.

All in the family: With the exception of Wright, the Lions were able to retain the core of their 10-6 team. Among those who re-signed: Tackle Jeff Backus, safety Erik Coleman, defensive end Andre Fluellen, quarterback Shaun Hill and linebacker Stephen Tulloch. And don't forget that receiver Calvin Johnson is locked up for perhaps the rest of his career. He signed a new eight-year contract worth $132 million.

What's next: The Lions appear interested in adding competition at safety, having hosted free agent O.J. Atogwe earlier this month. Adding a safety remains a possibility, if not through free agency, then probably through the draft. And while Backus is re-signed for two years, it wouldn't be surprising if the Lions look for a long-term replacement in the draft.

Green Bay Packers

Key additions: Defensive lineman Daniel Muir, center Jeff Saturday, defensive lineman Anthony Hargrove.

Key losses: Quarterback Matt Flynn, center Scott Wells.

Shocker: The Packers usually do whatever it takes to keep their own players and avoid having to search the free-agent market for other the castoffs of other teams. They started off that way by re-signing tight end Jermichael Finley to a two-year contract, but when they were unable to sign center Scott Wells, they quickly targeted veteran Jeff Saturday and made him their first starting-caliber free-agent signee in five years. General manager Ted Thompson also authorized the acquisition of Hargrove and the pursuit of Dave Tollefson.

What's next: It's not out of the question that the Packers will add a veteran pass-rusher, whether at defensive end or linebacker. Then they'll get back into their comfort zone and start preparing for the draft, where it's reasonable to think they'll use at least one of their 12 picks on a center while also continuing to pursue pass-rushers.

Minnesota Vikings

Key additions: Cornerback Zack Bowman, tight end John Carlson, running back Jerome Felton and offensive lineman Geoff Schwartz.

Key losses: Nose tackle Remi Ayodele (release), guards Anthony Herrera (release) and Steve Hutchinson (release), tight end Jim Kleinsasser (retire), running back Jerome Felton.

Methodical methodology: The Vikings made one big-money signing, bringing in Carlson as a new weapon for quarterback Christian Ponder, and otherwise have spent their offseason getting younger and signing complementary players. General manager Rick Spielman wants to end a cycle of seeking blue-chip players via free agency and instead count on the drafts for his difference-makers.

What's next: One way or the other, the Vikings need to find a deep threat for Ponder. The draft would seem the most likely place for that will happen. They are also midway through a rebuild of the secondary that could use at least one more cornerback and perhaps two safeties.