There was always someone leading the pack who was not going to get caught, which is why Rod Smith, generic in name, is also very much generic in deed. He might as well have “backup’’ stamped across his forehead, given the running backs he has sat behind.

Carlos Hyde and Ezekiel Elliott in college. Marshawn Lynch, Darren McFadden, Alfred Morris — and Elliott, again — in the NFL. And now, perhaps the greatest impediment to ever seeing the field, the one and only Saquon Barkley.

“Saquon’s a pro, he understands more than your average 22-year-old,’’ Smith told The Post. “He asks me all type of questions. Whenever he asks me I tell him what I know, being behind all the great backs I’ve been behind since I’ve been in the league. I throw what I know at him and he somehow puts his own flavor on it.’’

Barkley’s flavor makes him the alpha in the offensive backfield and there is not much room for anyone else to maneuver. Smith, 27, signed as a free agent to a one-year deal worth $805,000, was an understudy the past four years with the Cowboys and is looking to fill a similar role with the Giants.

His pathway to the roster is not straight and true. Wayne Gallman is a draft pick (fourth round in 2017) and a solid and young (24) reserve. Paul Perkins, a fifth-round pick in 2016, returns after spending last season on injured reserve and looks serious about sticking. Perkins has caught nearly everything thrown his way this summer and recently made one of the plays of training camp, sprinting downfield on a go-route to haul in a 50-yard pass from rookie Daniel Jones.

It is likely Smith and Perkins are fighting for the same spot. Smith, at 6-foot-3 and 236 pounds, provides bulk and power, but probably not enough to threaten Eli Penny, a 250-pound fullback.

“Me, I don’t feel any challenge,’’ Smith said. “Just come in and keep learning the playbook as quick as possible. I’m one of those guys you know you always can count on for special teams. I’m a guy that can come in when the head guy needs a break and you ain’t gonna miss a beat. But I don’t feel any challenge. I’m not worried about that.’’

Smith’s best NFL game came against the Giants in 2017 while Elliott was sitting out a six-game suspension. Smith ran for 47 yards and a touchdown and had a career-high 113 receiving yards, including an 81-yard touchdown, in a 30-10 Cowboys victory.

“It was my first real opportunity with people being out of the lineup that game, it was my opportunity to show what I can do,’’ Smith said. “When that opportunity comes you want to already be prepared. Yeah, it was a good game.’’

In the 2018 regular-season finale, with Elliott resting for the playoffs, Smith rushed for another touchdown on the Giants.

At Ohio State, Smith never emerged from the pack, scratching out playing time behind Hyde and later Elliott, and fell into disfavor resulting in two suspensions. He subsequently was kicked off the team as a senior after failing a drug test. Smith went undrafted and spent his rookie year in Seattle, where, just as in college, he sat behind a greater talent in Lynch.

Smith says Lynch is unique based on “the style of his vision, his vision was crazy, he didn’t miss too many cuts.’’ McFadden was “just flat-out a pro, on the field and off the field.’’ Morris is “just a good football player and also a great man. His running style, he led the NFL his first two years in the league.’’

Elliott?

“Just that confidence, that swagger, that demeanor,’’ Smith said. “He doesn’t even have to talk too much.’’

Based on one offseason of observance, Smith sees Barkley as capable of vaulting them all.

“I think Saquon has all the talent in the world, he can go down as one of the greatest,’’ Smith said. “He got all the right stuff.’’

Smith is not interested in a detailed comparison of the Cowboys and Giants, saying, “Every organization got their own type of style.’’ He likes what he sees in his new surroundings as he tries to stay around.

“It’s a first-class organization, they really take care of their guys here, everybody’s just trying to get better,’’ Smith said. “Everybody’s here to help, not just to get by. They’re really together, it’s a true team and I love that type of environment because I’m a team player. I may not always be the one in the paper but I’m going to make a play, I’m going to stand out some way, even if I don’t get recognized for it. You’re gonna know that I was playing.’’