The Pittsburgh Steelers hit free agency hard last year, bringing in a handful of veteran players to earn starting roles and improve depth.

Here is a position-by-position look at the Steelers depth chart going into this year's March 10 start of free agency.

PITTSBURGH -- The Steelers have just two nose tackles, and neither has harkened memories of run-stopper, gap-plugger extraordinaire Casey Hampton.

Steve McLendon has spent the past two seasons as the starter and has been average more often than not with occasional flashes of above average play. When he was Hampton's backup, many believed he could eventually fill Hampton's shoes. However, for a player who has been with the organization since 2010, the time has come for McLendon to pay off.

Steelers 2015 Depth Chart Review Reviewing where the Steelers stand in terms of depth heading into free agency and the draft.

McLendon has to do more. No one expected him to be Hampton, a Pro Bowl-caliber player for the majority of his career and amazing locker room presence. But he has been largely invisible for long stretches, despite a strong work ethic and weight-room regimen. This is the final season of McLendon's three-year contract he signed in 2013, and he'll count $2.81 million toward the cap. So, this could be it for him.

McLendon's future likely depends on how well big Dan McCullers does after a decent rookie season where the 6-foot-7, 352-pound behemoth showed some promise and steadily improved toward the end. The Steelers are in control of his contract, which is minimal, for three more seasons. A sixth-round pick last year, McCullers played in nine games and figures to have more of an impact this season. At least the Steelers are hopeful that happens.

Surely, this is an area where the Steelers will continue to look at players to fill the middle of their front line in the three-four defense. If that comes in the NFL Draft, don't expect the pick to be in the upper half of the selections.