Pittsburgh Steelers preview (No. 17): A new defensive identity

Our 2015 NFL preview series ranks every team, from worst to first. Today: the No. 17 Steelers.

2014 record: 11-5 (Lost in wild-card round to Ravens)

Head coach: Mike Tomlin (ninth season, 82-46 in regular season, 5-4 in playoffs)

Key arrivals: DeAngelo Williams (running back), *Sammie Coates (wide receiver), *Bud Dupree (outside linebacker), *Senquez Golson (cornerback)

 (*denotes rookie)

Key departures: Ike Taylor (cornerback), Troy Polamalu (safety), Jason Worilds (outside linebacker), Brett Keisel (defensive end), Brice McCain (cornerback), Lance Moore (wide receiver), Ben Tate (running back)

2015 schedule (ET):

Sept. 10: at New England, 8:30 p.m.

Sept. 20: San Francisco, 1 p.m.

Sept. 27: at St. Louis, 1 p.m.

Oct. 1: Baltimore, 8:25 p.m.

Oct. 12: at San Diego, 8:30 p.m.

Oct. 18: Arizona, 1 p.m.

Oct. 25: at Kansas Cit,y 1 p.m.

Nov. 1: Cincinnati, 1 p.m.

Nov. 8: Oakland, 1 p.m.

Nov. 15: Cleveland, 1 p.m.

Nov. 22: BYE

Nov. 29: at Seattle, 4:25 p.m.

Dec. 6: Indianapolis, 8:30 p.m.

Dec. 13: at Cincinnati, 1 p.m.

Dec. 20: Denver, 4:25 p.m.

Dec. 27: at Baltimore, 8:30 p.m.

Jan. 3: at Cleveland, 1 p.m.

TRAINING CAMP QUESTION: How soon can Bud Dupree help improve the pass rush?

Dupree said on SiriusXM NFL Radio that he has quickly learned the playbook elements installed during the offseason by new defensive coordinator Keith Butler. A 4-3 defensive end at Kentucky, Dupree hopes his transition is accelerated by working exclusively at left outside linebacker. "I started off trying to learn both sides, but I'm going to stick on the left side trying to win my way in," Dupree said. "You tend to focus on one thing, there's no telling how far my ceiling is right now." Dupree, James Harrison, Arthur Moats and 2013 first-round pick Jarvis Jones are competing for Pittsburgh's two starting outside linebacker spots as the Steelers try to better last season's 33-sack total, which was the franchise's lowest since 1988.

IF EVERYTHING GOES RIGHT

The Steelers offense continues to run hot as wide receivers Martavis Bryant and Markus Wheaton take the next step to a form a truly terrifying group with Antonio Brown. Ben Roethlisberger, with all the weapons at his disposal, has an All-Pro season and helps pick up the slack for a young defense. Speaking of the D, rookies Dupree and Senquez Golson contribute right away while Ryan Shazier, Stephon Tuitt and Jarvis Jones provide leadership for a unit that underwent a massive overhaul this offseason.

IF EVERYTHING GOES WRONG

The young defense crumbles without the leadership of departed stars Troy Polamalu, Brett Keisel and Ike Taylor. The offense is forced to try to outscore opponents every week minus injured All-Pro center Maurkice Pouncey as the defense fails to stop anyone. With three out of their final four games on the road against division opponents, the Steelers stumble down the stretch and miss the postseason.

BREAKOUT PLAYER: Defensive end Cameron Heyward

Heyward recently told Sports Illustrated that he thinks of himself as a "bust" despite coming off a season in which he became the first Steelers defensive end to tie or lead the team in sacks (7.5) in almost 30 years. In truth, Heyward is on the cusp of establishing himself as one of the NFL's top three or four ends headed into the 2015 season.

CIRCLE THE DATE GAME: at New England in Week 1 (8:30 p.m./Sept. 10)

A quarterback duel pitting Roethlisberger vs. Jimmy Garoppolo isn't nearly as sexy if New England's Tom Brady remains suspended. But the Steelers have their own player absence to worry about with running back Le'Veon Bell suspended in a game that could influence the AFC playoff race down the road.

ALEX MARVEZ'S PREDICTION: 9-7, third place

In retrospect, the 2014 seasons of both the Steelers and Cincinnati Bengals ended before both were eliminated in the playoffs. A Week 17 game between Pittsburgh and Cincinnati resulted in each team losing a key offensive piece in Bell (ankle) and Bengals wide receiver A.J. Green (concussion).

Defensively, the Steelers are a bigger question mark than in any of the past 11 seasons when Dick LeBeau was serving as coordinator. Butler takes over a unit that statistically ranked among the Steelers' worst in decades when it came to stopping the pass and registering sacks. The changing of the guard began in the offseason when Polamalu and Taylor retired. Butler needs some of Pittsburgh's young defenders, particularly outside linebackers Jarvis Jones and Dupree, to make an impact for his unit to show marked improvement.