PITTSBURGH — All of the work the Pittsburgh Steelers have done over the past three offseasons will have to continue despite the fact that they broke out of those consecutive 8-8 records to win the AFC North at 11-5.

Most of that will have to come on defense, where their 33 sacks ranked 26th in the NFL and were their fewest in 24 seasons. They also failed again to come up with many turnovers (21) and their defense ranked 15th overall, 18th in points and 27th vs. the pass.

Look for them to go without Troy Polamalu, Ike Taylor, Brett Keisel and perhaps James Harrison from that defense next season. Those four have been to all three Super Bowls since 2005 and have two rings each.

While the process will continue on defense, their offense needs very little. They finished as the NFL’s No. 2 offense in 2014 and boasted the NFL’s passing yards co-leader in Ben Roethlisberger, the leader in receptions and yards in Antonio Brown and the AFC rushing leader in Le’Veon Bell.

Their offensive line solidified and played well and they have some young dynamic receivers behind Brown in rookie Martavis Bryant and Markus Wheaton. About the only things they need on offense are a backup running back and tight end.

“Just because we have some outstanding front-line guys on offense, it doesn’t mean that we can’t get better,” Mike Tomlin said. “It might be as simple as fortifying depth in some positions.”

It was a successful season for Tomlin and his team after worries that they might be headed the other way following those twin 8-8 killings, which did not go over big in Pittsburgh. While their playoff loss at home to Baltimore was deeply disappointing, they realize they have work to do on defense if they want to take the next step back to the Super Bowl.

“I think that we’re a much better team at the end of the journey than we were at the beginning,” Tomlin said. “The growth and the development of young players and the etching out of roles and guys ascending is a part of that.

“We have a lot of guys that took big positive steps in 2014. As I reflect on the journey that is that season, I do feel comfortable about the growth of a lot of men and a lot of things to be proud and be excited about.”

Their offense carried them for most of the season, although it disappeared at strange times — e.g., a 20-13 loss at the Jets and a 31-10 loss at Cleveland. The offense may have to do it again in 2015 unless a lot of young players step up, including their past two first-round draft choices, Jarvis Jones and Ryan Shazier.

The Steelers will have a brutal schedule in 2015, having to play at New England, Seattle, Kansas City and San Diego, and at home vs. San Francisco, Arizona, Denver and Indianapolis.