At 34 years old last season, Gore toted the rock 261 times, 71 more rushing attempts than the rest of the Colts' squad combined (including 63 by QB Jacoby Brissett), and 168 more carries than the No. 2 back Marlon Mack (93 attempts).
With Gore gone, the door is open for Mack to take on a larger role in 2018.
"I feel like, for me, it just motivates me to just go harder," Mack told the team's official website. "Other guys in the room feel the exact same as me. Everybody wants to be the top dog, and so you've just got to [be motivated] and just be hungry and attack; attack, I'd say, just show your talents and do your best."
Mack currently sits as the clear top dog in the running back room. Behind Mack sits a gaggle of backs who either have less experience than the second-year pro or washed out at their previous spot for various reasons: Matt Jones, Christine Michael, Robert Turbin, Josh Ferguson, George Winn. Indy is a strong candidate to add a running back at some point during the NFL draft later this month from what is expected to be a deep class at the position.
As it currently stands, the shifty Mack is in line to more than double his usage from last season. The 22-year-old South Florida product is the type of dual-threat NFL coaches love. At times last season, Mack was a highlight machine, including a nine-carry, 91-yard performance in Week 5 versus the 49ers. The rookie, however, had his struggles. A propensity to try and hit home runs and bounce everything outside led to far too many negative and no-gain attempts. Mack, as most rookies do, also struggled with pass protection.
New Indy coach Frank Reich spent the past two seasons in Philadelphia, where they deployed a heavy running back rotation, utilizing each player's strength.
"Yeah, definitely excited to see how they did it over there at the Eagles, because they used, like you said, a bunch of backs, and that's something you can be happy about because everybody's going to eat, and they work together as a team," Mack said. "No matter who's in or who's out right now, everybody's got to up to the plate and work together as a team."
There are legitimate questions about whether Mack can be the every-down, between-the-tackles runner the Colts needs, but he should get the first chance to grab the reins. With Andrew Luck returning after missing last season with a shoulder injury, Indy desperately needs a steady rushing attack to buoy the offense in 2018.