INDIANAPOLIS —An open spot atop the depth chart is motivation enough for Marlon Mack.
With the departure of veteran Frank Gore, who signed with the Miami Dolphins this offseason after spending the past three seasons as the Indianapolis Colts' starting running back, Mack enters his second season in the NFL much more comfortable in his surroundings — not to mention much more confident about his abilities.
But while Mack appears to be the next in line to get the starters' reps at running back, the team has started anew with the hiring of head coach Frank Reich, who brings with him a completely new offensive playbook for the players to master.
Mack said everybody in the Colts' running backs room is getting a clean slate, meaning every little detail — from the start of the team's offseason workout program this week through training camp and the preseason — is critical.
"I feel like, for me, it just motivates me to just go harder," Mack told Colts.com this week. "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."
In his rookie season with the Colts, Mack certainly showed flashes of the big-play abilities he displayed during his career at South Florida, where he finished as the school's all-time leader in rushing yards (3,609) and rushing touchdowns (32).
But the Bulls featured a much more spread out offensive attack, giving the speedy Mack plenty of opportunities to make most of his plays out in space. Once he came to the Colts, who selected him in the fourth round of last year's NFL Draft, Mack had to begin to learn how to translate his abilities as a scatback into more of a pro-style offense, where you can't always bounce the play outside against defenders you know you can out-run.
Playing as a change-of-pace back behind Gore in 2017, Mack had some sensational moments, including a nine-carry, 91-yard, one-touchdown performance in a Week 5 victory over the San Francisco 49ers, a terrific 24-yard touchdown reception Week 8 against the Cincinnati Bengals and, last but not least, a ferocious stiff arm that sent Houston Texans edge defender Jadeveon Clowney to the turf in Indy's Week 17 victory over their AFC South Division rivals.
But Mack's rookie season also showed plenty of evidence of things he needed to work on. While he had carries of 35, 25, 24, 22, and 20 yards on the year, Mack also ran into a bit of a buzzsaw at times; heading into Week 16, he had carries of no gain or negative yardage on 34.1 percent of his rushing attempts, according to Pro Football Focus, which was the highest rate among all NFL running backs with at least 75 carries on the year.
Mack also had some early struggles in pass protection and in identifying possible blitzers, but showed marked improvement in those areas throughout the season.
"I feel like I've progressed real well, especially coming in and just adjusting to the NFL level as guys reading the schemes and understanding the defensive fronts and things like that," Mack said. " I feel like progressed well, because coming in, it was something I really didn't do in college, and I come here and I learned it and picked it up pretty well. …. I knew it was coming, so I pretty much picked it up pretty well for me."
Mack used his first full NFL offseason to bulk up to assist in those assignments against the larger defenders, and said he's worked with team nutritionist Anna Turner, as well as the strength staff, to add a few pounds to his frame 6-foot, 210-pound frame.
"I've been trying to follow a great plan she's got for me, and just trying to pick up a few pounds, (be) a little heavier guy. So I try to get as much as I can," he said. "I mean, a few pounds won't hurt me, so I feel like that's a good thing for me."
Mack is also excited to see what Reich and new coordinator Nick Sirianni have in store for the offense. Reich is coming off a season in which he was offensive coordinator of one of the top units in the league, the Philadelphia Eagles, who utilized multiple running backs in various situations to eventually claim the franchise's first-ever Super Bowl title.
"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."