Ranking the 2015 Impacts of the Pittsburgh Steelers' Free-Agent Signings So Far

The Pittsburgh Steelers have made only four free-agency signings thus far, a low number that is par for the course for a team that prefers to build through the draft.

How much of an impact will these four signings have on the Steelers' 2015 season? Based on projected snaps played and the importance of their respective positions, we can take a stab at guessing how heavily involved each will be this season. 

4. TE Matt Spaeth

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Of the Steelers' four free-agent signings thus far, tight end Matt Spaeth ranks fourth in projected impact on the 2015 season. That's not to say that he won't be an important part of the offense, but given his playing time and his specialized role, he gets slotted into the fourth spot on this list.

Spaeth isn't a receiving tight end—he has just 53 total receptions for 410 yards and 10 scores over the course of his eight seasons in the NFL and caught only three passes for 46 yards and a touchdown in 2014. Where he excels, however, is as a run-blocker.

According to Pro Football Focus, Spaeth played 361 snaps, 31.3 percent of the Steelers' offensive total last year. However, 210 of those were spent as a run-blocker, and his positive-4.1 grade in that area had him tied for Pro Football Focus' 17th-best tight end of the 2014 season, ahead of teammate Heath Miller.

Given how important the run game has become to the Steelers with the emergence of Le'Veon Bell, Spaeth's limited, specialized role is a big one. But because he's a one-dimensional player who is on the field for only one third of the team's offense snaps, his 2015 impact should be the lowest of the Steelers free-agency signings.

3. RB DeAngelo Williams

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One necessary move the Steelers needed to make in free agency this year was to add a veteran running back, and they did just that by bringing in DeAngelo Williams, who has nine years of experience with the Carolina Panthers.

Williams has a career total 1,432 carries for 6,846 yards and 46 touchdowns, giving him a 4.8-yards-per-carry average. He has also caught 178 passes for 1,621 yards and seven scores.

Williams is a complementary piece for the Steelers' roster, much as LeGarrette Blount was last year before he walked out on the team and was subsequently cut. However, Williams isn't a threat to give up on the team, with Steelers general manager Kevin Colbert saying to Mark Kaboly of the Pittsburgh Tribune-Review that "his character and his willingness to be a contributor really sealed the deal for us."

The Steelers met a clear need by picking up Williams. Though he's not going to be the Steelers' lead back, he'll provide mentorship for Bell and a contrasting running style that will round out Pittsburgh's offense.

2. OLB Arthur Moats

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The Steelers' first step to insuring proper outside linebacker depth for 2015 was to re-sign Arthur Moats. Moats, who joined the Steelers as a free agent in 2014, totaled 17 combined tackles and four sacks in a rotation that also features Jarvis Jones (who missed time with a broken wrist), James Harrison and Jason Worilds.

Now it appears Moats is about to take on a larger role, potentially being a three-down linebacker on the left side, unless the Steelers opt to draft a linebacker and plan on giving him starting snaps.

Either way, the signing of Moats met an immediate and glaring need. Without him—and without Harrison, who was also re-signed—the Steelers would have only Jones on the roster as an outside linebacker. This was a smart signing of a player who has earned another contract and increased playing time in Pittsburgh.

1. OLB James Harrison

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Though Moats was clearly a need-based re-signing that was worth both the Steelers' money and effort to get done, considering how well he performed in 2014, the re-signing of James Harrison is the highest-impact free-agency move they've made thus far.

Granted, Harrison turns 37 years old in May and has already retired once. However, he seemed almost ageless in 2014, totaling 5.5 sacks and 29 combined tackles on 491 snaps played and four starts, per Pro Football Focus. He knows the defense better than any other player the Steelers could hope to add and is willing to take on a mentorship role, not just for Jarvis Jones but for the other young Steelers defenders, as evidenced by his open invitation to many of them to work out with him in Arizona, according to Mark Kaboly of the Pittsburgh Tribune-Review.

Mentoring won't be Harrison's only role in 2015, however. It looks as though there will be competition between him and Jones to be the team's starting right outside linebacker this year, and even if Jones does win the job, Harrison will still be there to spell him on a situational basis.

Harrison may not have many years left in the NFL—in fact, it is somewhat surprising he wants to play this season. But that's a boon for the Steelers, who desperately needed not just help at outside linebacker but also someone who understands the defensive system in and out. They'll certainly get that from Harrison in 2015.