PITTSBURGH (AP) ― Steelers coach Mike Tomlin acknowledges that change is inevitable, even for one of the NFL’s most stable franchises.

This offseason could be bumpier than most.

Pittsburgh’s stunning 29-23 playoff loss to Denver last Sunday put an end to a 12-5 season that felt underwhelming by the team’s lofty standards.

The AFC champions played from behind all year, getting drummed by rival Baltimore in the season opener and never quite catching up. Though the Steelers steadied themselves after a so-so September, they struggled to stay healthy.

Quarterback Ben Roethlisberger and linebackers James Farrior and James Harrison were among the starters who dealt with significant injuries while defensive end Brett Keisel and nose tackle Casey Hampton could require offseason surgery.

The Steelers persevered, becoming one of three teams from the AFC North to advance to the postseason.

But it’s over early this time around, and with seven defensive starters in their 30s, the Steelers could go through a significant transition before the 2012 season kicks off.