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Roosevelt Nix provided a considerable amount of value during his time with the Steelers

Nix, a defensive lineman in college before moving over to fullback upon entering the NFL, helped pave the way for Le'Veon Bell during their time together in Pittsburgh. With Nix as his fullback, Bell earned Pro Bowl and All-Pro honors while setting Steelers regular and postseason single game rushing records. Nix's contribution to Bell's success led to him earning Pro Bowl honors in 2017. Nix also served as a team captain in 2019, his final season in Pittsburgh. 

After helping Bell (and James Conner, a Pro Bowler during the 2018 season) become among the league's best running backs, Nix, who signed with the Colts this past weekend, is hoping to do the same for Marlon Mack, who rushed for a career high 1,091 yards last season despite missing two games with a broken hand. 

"Just very excited — you know, they haven't had a fullback in a while — and I'm excited to be a guy they take a chance on," Nix told the team's official website. "The game is a tough game, won in-between the trenches, and the Colts, we've got a great offensive line, we're gonna put me back there, and Marlon Mack, like I said, is already an outstanding running back, so I'm just excited to see what happens; excited to see how this plays out."

The Colts are surely hoping that Nix, the team's first fullback since 2013, will help create for running lanes for Mack, a fourth-round pick in the 2017 draft who is entering the final year of his rookie contract. With Mack leading the way, the Colts finished seventh in the NFL in rushing last season, averaging over 133 rushing yards per game. 

The Colts were reportedly in talks of extending Mack's contract earlier this offseason. Indianapolis general manager Chris Ballard discussed Mack's future with the team back in February. 

"Part of our offseason evaluation (is) -- we know, we're going to try to take care of our own -- so who are guys that we want to extend?" Ballard said, via Jim Ayello of the Indianapolis Star. "Marlon, look, he easily could have missed more games (with his broken hand), but he didn't. He fought to get back in because he wanted to play."

Mack has also expressed a desire to remain with the Colts, who are looking to get back to the postseason in 2020 after a disappointing 7-9 season in 2019. 

"In this league, as a running back, you gotta strike fast," Mack said late in the 2019 season with regard to his contract situation. "You don't strike fast, that's it for you. You're too old at (27-years-old). … Running backs, man, running backs don't always get treated well. Running back is an important position. I hope people can learn that one day. I don't know when it fell off (for us), but I need it to go back up (laughs). Hopefully it happens one of these days." 

While he still does not have a new contract, Mack has a golden opportunity to elevate his market value if he is able to enter free agency next offseason. Not only does he have one of the NFL's best offensive lines playing in front of him, he also has Philip Rivers, who signed a one-year deal with the Colts last month. Mack also has a new fullback in Nix, who is hoping to add to his list of Pro Bowl running backs that he has blocked for during his NFL career. 

Nix is also hoping to dispel the notion that the fullback position is no longer an important part of an NFL team

"I just think the stigma of the fullback is dying," Nix said. "I think the position in itself is changing; I think you have to be able to do a lot of things and kind of be a hybrid player."