Carolina Panthers preview (No. 4): Defense will lead the way

Our 2015 NFL preview series ranks every team, from worst to first. Today: the No. 4 Panthers.

2014 record: 7-8-1 (lost to Seahawks in divisional round of playoffs)

Head coach: Ron Rivera (fifth year, 32-31-1 regular season, 1-2 playoffs)

Key departures: Thomas DeCoud (safety), DeAngelo Williams (running back), Greg Hardy (defensive end)

2015 schedule (ET)

Sept. 13: at Jacksonville, 1 p.m.

Sept. 20: Houston, 1 p.m.

Sept. 27: New Orleans, 1 p.m.

Oct. 4: at Tampa Bay, 1 p.m.

Oct. 18: at Seattle, 4:05 p.m.

Oct. 25: Philadelphia, 8:30 p.m.

Nov. 2: Indianapolis, 8:30 p.m.

Nov. 8: Green Bay, 1 p.m.

Nov. 15: at Tennessee, 1 p.m.

Nov. 22: Washington, 1 p.m.

Nov. 26: at Dallas, 4:30 p.m.

Dec. 6: at New Orleans, 1 p.m.

Dec. 13: Atlanta, 1 p.m.

Dec. 20: at N.Y. Giants, 1 p.m.

Dec. 27: at Atlanta, 1 p.m.

Jan. 3: Tampa Bay, 1 p.m.

IF EVERYTHING GOES RIGHT

The Panthers have won the NFC South two straight seasons -- by force in 2013 and by default a year ago. The team's 3-8-1 start to 2014 never felt as real as its 4-0 finish and wild-card playoff victory, so there's reason for optimism even if those five wins were against lackluster opponents. A healthier quarterback Cam Newton got some receiving help when the Panthers drafted Devin Funchness, and Carolina's defense will always be strong with Luke Kuechly at middle linebacker and Ron Rivera calling the shots.

IF EVERYTHING GOES WRONG

Newton brings a 30-31-1 record as a starter into his fifth NFL season, and Carolina won't take the next step if he doesn't. A repeat of his 18-touchdown, 12-interception 2014 season might make the Panthers start wondering whether he'll ever live up to his No. 1 overall draft billing. When those types of concerns start floating about a franchise quarterback, seasons have a way of falling apart.

BREAKOUT PLAYER: Defensive end Kony Ealy

The Panthers drafted Ealy in the second-round last year knowing there was a good chance defensive end Greg Hardy wouldn't be back. With Hardy now gone to Dallas, Ealy is a strong candidate to win the starting role outright after playing off the bench in 2014.

CIRCLE THE DATE GAME: Week 6, at Seattle (4:05 p.m. ET/Oct. 18)

Getting over the hump against Seattle would be a strong statement that the Panthers are a bona fide Super Bowl contender. Carolina quarterback Cam Newton has lost all four of his career starts vs. the Seahawks, including last season's second-round road playoff game.

ALEX MARVEZ'S PREDICTION: 10-6, first place

Defense is again Carolina's strength, especially at linebacker where veterans Kuechly and Thomas Davis will be joined by first-round draft pick Shaq Thompson. Like last season, the line and health of running back Jonathan Stewart are the biggest offensive concerns. The Panthers are gambling that Michael Oher can rebound from a poor 2014 season in Tennessee to protect Newton's blind side at left tackle. Oklahoma rookie right tackle Daryl Williams is the front-runner to start at right tackle. Stewart helped spark Carolina's late-season push last December and rushed for 193 yards in two playoff games. Stewart, though, hasn't played in all 16 regular-season games since 2011 because of injuries. In two seasons, the Panthers have made two second-round playoff appearances. Success will be measured for the 2015 Panthers by whether the franchise can advance beyond that point.