Butler has big shoes to fill in the wake of LeBeau's departure. He's not married to the team's traditional 3-4 defense and he'll have a host of fresh faces to help pick up the pieces from last season's down year. With the offense expected to be one of the best in the league, Butler doesn't have to bring back the Steel Curtain just yet, but it will be interesting to see how much he changes things up from LeBeau's philosophy. Whatever the system, this unit needs to make plays after recording just 33 sacks (26th in the NFL) and 11 interceptions (25th) in 2014.
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The early frontrunner to replace Troy Polamalu is Shamarko Thomas. Problem is, Thomas has battled injuries in two seasons as a backup. If Thomas hasn't been able to stay on the field in limited duty, how can he be counted on full time? Veteran Will Allen is the other main option, but there is little NFL experience once you get past him. The Steelers can ill afford deficiencies on their back line after finishing 27th in the league with 86 big plays allowed last season, according to SportingCharts.com.
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Where will the pass rush come from?
Defensive end Cameron Heyward just signed a massive contract extension after sharing the team lead with 7.5 sacks last season -- not bad for a guy whose role was to take on blockers rather than shed them. Does a new coordinator mean that Heyward will be unleashed on opposing quarterbacks? The Steelers will need more than the 33 sacks they had last year, and Heyward is the best answer. Jason Worilds is no longer around, James Harrison will likely be on a snap count, and who knows what to expect from Jarvis Jones.
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Pittsburgh is certainly hoping that first-round pick Bud Dupree becomes the answer to its pass-rushing problems. The preseason will give us an early barometer of how his freakish athletic ability will translate at the NFL level. Corner Senquez Golson, a second-round pick, can make an impact as a nickel corner. Sammie Coates is hoping to be this year's version of Martavis Bryant, and it will be interesting to see how Todd Haley works Coates and 6-foot-7 tight end Jesse James into the offense.
Can DeAngelo spell Bell?
DeAngelo Williams will have to carry the load with Le'Veon Bell suspended for the first three games of the season. Steelers fans will be eager to see if Williams is capable after he missed 10 games last year due to various ailments. Williams, who has split time with Jonathan Stewart for the past seven years, hasn't rushed for 1,000 yards since 2009. Filling Bell's shoes is likely impossible, but if Williams can have a productive 15 touches per game and pass protect, Ben Roethlisberger and company will be in good shape.