A punishing Indianapolis Colts running game has added another hammer, a blunt force instrument to blow open holes in front of Marlon Mack, the first Indianapolis running back to break the 1,000-yard barrier since Frank Gore in 2016.

The Colts are signing former Pittsburgh Steelers fullback Roosevelt Nix, a league source told IndyStar, bringing back an element of the 2018 offense that wasn’t as prevalent in 2019.

Nix, a collegiate defensive end who spent a season in the Arena Football League before earning a permanent spot in Pittsburgh, is part of a rare breed in the NFL these days: A fullback who does most of his work as a blocker.

The 5-foot-11, 248-pound Nix spent five seasons in Pittsburgh and played 575 offensive snaps for the Steelers, but he rarely touched the ball, carrying the ball just four times and making 12 receptions, never more than four in a season.

But there is precedent for a lead blocker like that in Frank Reich’s offense. Back in 2018, the Colts signed former Bengals tight end Ryan Hewitt after final roster cuts and used him mostly as a fullback. Hewitt played 182 snaps for the Colts offense that season and touched the ball only once, a 1-yard touchdown grab in the regular-season finale.

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The rest of the time, Hewitt was a road-grader.

Without a player like Hewitt on the roster last season, Indianapolis used the “fullback” position less, even as a Mack-led running game became the first Colts team to rush for more than 2,000 yards in a season since 1994. With no “fullback" on the roster, the tight end position has handled the role and was given 1,612 offensive snaps in 2018; the number dropped to 1,513 in 2019 despite the Colts’ commitment to the run game.

Nix opens some of those options up, adding a Hewitt-type player back to the offense, provided that the former Steelers fullback is healthy after missing almost the entire season due to a knee injury last year. Nix was designated to return off injured reserve in late December, an indicator that he was healthy at the end of the season.

As talented a blocker as Nix is, he’s also an important addition in the kicking game.

Nix was a key special-teamer throughout his career with the Steelers, playing 1,078 snaps in the kicking game and eventually earning recognition as Pittsburgh’s special teams captain last season. In his four full seasons with Pittsburgh from 2015-2018, Nix made 34 tackles on special teams, forced two fumbles and blocked a punt.

In other words, the Colts added a hammer that can be used for more than just one job next season.