The final in a position-by-position series in advance of the start of free agency, which is at 4 p.m. ET on March 9:

DEFENSIVE LINE – (9)
(Free Agent Scorecard: 3 unrestricted – Clifton Geathers, Steve McLendon, Cam Thomas)

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CLIFTON GEATHERS**
After entering the NFL as a sixth-round pick by the Browns in 2010, Geathers bounced around among five teams – Cleveland, Miami, Dallas, Philadelphia, and Washington – before signing with the Steelers on Dec. 1, 2014. After completing that season, he re-signed with the Steelers the following April 1 and went to training camp last summer with a legitimate shot to make the roster as a backup defensive end. At 6-foot-8, 299 pounds, Geathers certainly stands out in a crowd, even if that particular crowd happens to be filled with professional football players. But despite showing some promise in his quest, Geathers was unable to make it to the start of the five-game preseason healthy, and he was placed on injured reserve on Aug. 7, the day before the Hall of Fame Game in Canton. Had he been able to stay healthy, it was looking like he would be someone to provide depth behind Cam Heyward and Stephon Tuitt. Now, who knows?

CAM HEYWARD
About to enter his sixth NFL season, Heyward's status among these Steelers now is similar to that enjoyed by Ben Roethlisberger, Antonio Brown, Le'Veon Bell, Maurkice Pouncey, and maybe a few others, and it's hard to argue that he isn't the No. 1 presence on the defense. As this particular group of Steelers works toward the seventh Lombardi Trophy in franchise history, Heyward is a key element both on the field and in the locker room. Getting Heyward with the second-to-last pick in the first round of the 2011 NFL Draft added a critical part of the foundation of this next wave of Steelers, and the selection deserves consideration as one of the best value choices of the Colbert-Tomlin era.

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LAVON HOOKS**
Signed on Feb. 16, Hooks, 6-foot-3, 312 pounds, entered the NFL with the Packers in May 2015 as an undrafted rookie, and he  spent that training camp with the team before being released on Aug. 31, 2015. When a team is looking for depth along the defensive line, it's wise to leave no stone unturned. We'll see what's under Lavon Hooks' stone.

CAUSHAUD LYONS
Lyons (6-5 , 284) played his college football Tusculum – the same program that produced Ricardo Colclough – and signed with Tampa Bay as an undrafted rookie in May 2015. After being waived by the Buccaneers as that preseason was winding down, he was claimed by the Steelers. Lyons spent some time on the 53-man roster but was inactive for each game. He was waived in a subsequent move that brought Anthony Chickillo up from the practice squad, and then Lyons was added to the Steelers practice squad once he cleared waivers. It's hoped Lyons has some of the raw athletic ability to contribute along the defensive line, but he is raw after playing his college football at a lower-level program. The days spent in Latrobe will be very important to him.

DANIEL MCCULLERS
It's going on year three for McCullers, a fan favorite partly because of his size – listed as 6-7, 352 – but that alone hasn't translated into a sizable amount of playing time. Last year even Joe Greene implored McCullers to make up his mind to utilize his size and strength to dominate opposing offensive linemen, but so far that hasn't happened on a consistent basis. One of the issues facing McCullers is that he has to figure out how to translate his skills into being a contributor as an interior defensive lineman in an increasingly pass-happy NFL. The Steelers are into this offseason and already are acknowledging a need for depth along the defensive line. Based on that, plus McCullers being one year closer to free agency, 2016 appears to be a crossroads for the former sixth-round draft pick from Tennessee.

STEVE MCLENDON
He came to the team as an undrafted rookie from Troy, and he was raw but willing to work to correct that. At the end of his sixth NFL season, McLendon was undoubtedly the third-best defensive lineman on the Steelers' roster. But at the end of his sixth NFL season, McLendon also is an unrestricted free agent. In my opinion, this is another of those instances when team and player are better off staying together through this most recent bout of unrestricted free agency, because there seems to be a mutual understanding/appreciation. But a contract must be negotiated, too.

CAM THOMAS
This is an example of a free agent signing that didn't work out. Added in 2014 with the idea he would provide depth at both nose tackle and defensive end, Thomas really wasn't accomplished enough at either position to earn enough trust from the coaches to end up with much playing time except when injuries struck. And his production decreased, from 19 tackles and one-half sack in 2014, to 11 tackles, no sacks, and no pressures in 2015. This would seem to be a situation in which the Steelers decide to move on, even with a stated need at the position(s) Thomas was signed to help.

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STEPHON TUITT**
Not only did Tuitt use his second NFL season to establish that he could play in the NFL, but he used his second NFL season to establish that he could be a playmaker in the NFL. In 2015, Tuitt finished with 54 tackles, 6.5 sacks, eight pressures, and a red zone interception early in a must-win December game against the Bengals in Cincinnati. Coach Mike Tomlin once said during those seasons when William Gay and LaMarr Woodley were terrorizing opposing offenses that when one made a play it would inspire the other to match it or better it. Looking at Tuitt and Heyward, imagine the possibilities should the same one-upsmanship develop.

L.T. WALTON
A sixth-round pick last year from Central Michigan, Walton squeezed onto the 53-man roster, primarily because the Steelers really didn't have any other options. Inactive for each of the first two games, Walton then went through a span of six straight weekends where he was in uniform and got into the games, but he didn't record a statistic in any defensive category. Walton then was inactive for seven of the next eight regular season games and both in the postseason. This seems to be a nice opportunity for Walton, what with the Steelers looking for players to eat into the snap totals that had to be amassed by Heyward and Tuitt last season, but because the team will be looking actively for help at Walton's position – possibly both during free agency and then the draft – there figures to be a lot of competition added to the mix. It will be telling to see how Walton responds to the situation.