Green Bay Packers

New faces: TE Matthew Mulligan, RB Eddie Lacy, RB Johnathan Franklin, G/C J.C. Tretter, DT Johnny Jolly.

Saying goodbye: WR Greg Jennings, TE Tom Crabtree, LB Erik Walden, S Charles Woodson, LB Desmond Bishop.

Youth movement: The Packers drafted Lacy (second round) and Franklin (fifth) in April in an effort to bolster a running game that ranked 20th in the NFL.

Best young player: WR Randall Cobb. With the departure of Greg Jennings, Cobb, 23, becomes the No. 1 target for quarterback Aaron Rodgers. A 1,000-yard season should be no problem.

Pressure’s on: LB Nick Perry. There were flashes of brilliance from the 2012 first-round pick, but knee and wrist injuries limited him to 197 snaps. He’ll be counted on to replace Walden this season.

Minnesota Vikings

New faces: WR Greg Jennings, LB Desmond Bishop, QB Matt Cassel, WR Cordarrelle Patterson, DT Sharrif Floyd.

Saying goodbye: WR Percy Harvin, CB Antoine Winfield, LB Jasper Brinkley, P Chris Kluwe, OL Geoff Schwartz.

Youth movement: The Vikings thought they could release Winfield and get him to re-sign for less than the $7.25 million he was owed, but instead he signed with Seattle. Josh Robinson, the fastest player at the 2012 combine, will get a chance to replace Winfield as the nickel cornerback.

Best young player: LT Matt Kalil. The fourth overall pick in 2012 made the Pro Bowl as a rookie and is the type of franchise left tackle NFL teams search for.

Pressure’s on: QB Christian Ponder. The Vikings brought in Greg Jennings as a No. 1 receiving target and Matt Cassel to serve as the backup, giving Ponder some help — and motivation.

Chicago Bears

New faces: LB D.J. Williams, OT Jermon Bushrod, TE Martellus Bennett, LB James Anderson.

Saying goodbye: LB Brian Urlacher, G Lance Louis, QB Jason Campbell, OL Gabe Carimi, DE Israel Idonije.

Youth movement: Urlacher’s retirement — after what he called an “insulting” offer from the team to return — ushered in a new era in Bears history. Draft pick Jon Bostic is being groomed to take over the position.

Best young player: DT Henry Melton. One of the few young players on an aging defense, Melton is coming off his first Pro Bowl selection. He has 13 sacks the past two seasons.

Pressure’s on: DE Shea McClellin. After playing just 35 percent of the snaps as a rookie, the Bears need McClellin — a first-round pick in 2012 — to develop into a quality pass rusher opposite Julius Peppers.

Detroit Lions

New faces: RB Reggie Bush, S Glover Quin, K David Akers, DE Jason Jones, DE Israel Idonije.

Saying goodbye: DE Cliff Avril, DE Kyle Vanden Bosch, LB Justin Durant, OT Jeff Backus, K Jason Hanson.

Youth movement: Second-year WR Ryan Broyles caught 22 passes for 310 yards, but a torn ACL ended his rookie year prematurely. If Broyles is 100 percent, he should pass Nate Burleson as the Lions’ No. 2 receiver behind Calvin Johnson.

Best young player: DT Ndamukong Suh, left.

Pressure’s on: LT Riley Reiff. The Lions’ 2012 first-round pick will move from the right side to replace the retired Backus. Reiff has to show he’s up for playing left tackle in the NFL. – J.S.