New faces: DT Kevin Williams, QB Terrelle Pryor, WR Kevin Norwood, DE Cassius Marsh, OT Justin Britt.
Saying goodbye: DE Chris Clemons, DE Red Bryant, DT Clinton McDonald, CB Walter Thurmond, G Paul McQuistan, OT Breno Giacomini, WR Golden Tate.
Projected starting quarterback: Russell Wilson. Wilson’s second-year stats: 16 starts, 257 of 407, 63.1 completion percentage, 3,357 yards, 8.2 yards per attempt, 26 TDs, 9 interceptions, 101.2 passer rating.
What they need to learn: How to repeat. Something that hasn’t been done in the NFL since the New England Patriots in 2004-05.
Did you know? The Seahawks last year were the fourth-youngest team in NFL history to win a Super Bowl.
They can repeat if: The offense can slowly transition from more of a run-first unit with Marshawn Lynch to successfully giving Wilson more responsibility.
They might take a step back if: Stopping the run becomes problematic. Letting Bryant go in favor of retaining edge rushers Michael Bennett and Cliff Avril could weaken the Seahawks in that area.
San Francisco 49ers
New faces: WR Brandon Lloyd, WR Stevie Johnson, S Antoine Bethea, CB Chris Cook, QB Blaine Gabbert, OL Jonathan Martin.
Saying goodbye: S Donte Whitner, CB Tarell Brown, CB Carlos Rogers, OL Jonathan Goodwin.
Projected starting quarterback: Colin Kaepernick.
Kaepernick’s second-year stats: 13 appearances (seven starts), 136 of 218, 62.4 completion percentage, 1,814 yards, 8.3 yards per attempt, 10 TDs, 3 interceptions, 98.3 passer rating.
What they need to learn: Are either of their promising young running backs, Marcus Lattimore or Carlos Hyde, ready to take over as the every-down option for Frank Gore?
Did you know? The 49ers have at least 11 wins in each of coach Jim Harbaugh’s first three seasons.
They’ll raise the Lombardi Trophy if: Kaepernick develops as a pocket passer and the defense gets both Aldon Smith and NaVorro Bowman back at 100 percent.
They’ll fall just short again if: The rebuilt secondary fails to come together and Kaepernick continues to run as hot and cold as he did in 2013.
New faces: OT Jared Veldheer, CB Antonio Cromartie, LB Larry Foote, TE John Carlson.
Saying goodbye: LB Karlos Dansby, RB Rashard Mendenhall, G Daryn Colledge, WR Andre Roberts, LB Matt Shaughnessy, S Yeremiah Bell.
Projected starting quarterback: Carson Palmer. Palmer’s second-year stats: 13 starts, 263 of 432, 60.9 completion percentage, 2,897 yards, 6.7 yards per attempt, 18 TDs, 18 interceptions, 77.3 passer rating.
What they need to learn: How to replace inside linebackers Dansby and Daryl Washington, who must serve a year-long suspension for violating the NFL’s substance-abuse policy.
Did you know? Carson Palmer is entering his second season as the Cardinals’ starting quarterback, the first player to do that since Kurt Warner retired after the 2009 season.
They’ll reach 10 wins if: Andre Ellington develops into the stud the Cardinals think he can be at running back, Palmer cuts down on his interceptions and the defense fills the holes at linebacker.
They’ll be under .500 if: The newly built offensive line, with four new starters from a year ago, lacks cohesion.
St. Louis Rams
New faces: WR Kenny Britt, QB Shaun Hill, DT Alex Carrington, OL Greg Robinson, DT Aaron Donald.
Saying goodbye: CB Cortland Finnegan, QB Kellen Clemens, DB Darian Stewart, G Chris Williams.
Projected starting quarterback: Shaun Hill. Hill’s second-year stats: No games played.
What they need to learn: How to live without quarterback Sam Bradford, who was lost for the year this summer because of a torn ACL – the same injury that ended his 2013 season.
Did you know? The Rams have recorded 50-plus sacks in each of the past two seasons.
They will go .500 if: The defense alone can steal them some games. The defensive front of Robert Quinn, Chris Long, Aaron Donald and Michael Brockers may be the best in the NFL.
They’ll pick top 10 if: The offense sputters under Hill and they don’t get more big plays out of Tavon Austin, their first-round pick in 2013.