GREEN BAY – Jack Heflin admits he has nothing to lose.

By most metrics, the small-town defensive lineman who had zero scholarship offers coming out of Erie-Prophetstown (Ill.) High School has already surpassed expectations by playing one NFL season.

But that doesn't mean it's enough.

One year after being the Cinderella story of training camp, Heflin remains every bit as hungry as he was last summer when the 6-foot-3, 304-pound defensive lineman became the only undrafted rookie to make the Packers' initial 53-man roster.

If being a lifelong underdog has taught Heflin anything, it's that valuable lessons are learned on roads paved through adversity.

"Just being undrafted, you have no choice. That's what it's been my whole life," Heflin said. "There's no plays off. If you're throwing me out there, I'm going to go until I can't go no more. I like to say I'm like a good dog. If you tell me to sic 'em, I'm going to sic 'em, even I'm not 100%."

A former walk-on at Northern Illinois University, Heflin parlayed three strong seasons for the Huskies and a graduate year at the University of Iowa into a once-in-a-lifetime opportunity with the Packers last summer.

Humble beginnings and a strong work ethic underscored Heflin's feel-good story last summer, with him leading the Packers' defense with five quarterback hits in the preseason.

Once again, Heflin is swimming against the strong tide of a position group that includes two-time Pro Bowl defensive tackle Kenny Clark, established veterans Dean Lowry and Jarran Reed, and rookie first-round pick Devonte Wyatt.

But that hasn't stopped the 24-year-old defensive lineman from rising to his level of competition. During last Friday's preseason opener against the San Francisco 49ers, Heflin racked up four tackles, including one for a loss, on 37 defensive snaps.

While Heflin was critical of his own performance – lamenting the plays he didn't make – Head Coach Matt LaFleur was complimentary of the second-year defensive lineman's outing.

"He did a nice job of shedding blocks and playing with his hands," LaFleur said. "I know a least one TFL and he made a couple other nice stops in the run game. He showed up. I thought he did a nice job."

As much of a factor as he was in camp last summer, Heflin played just 17 defensive snaps in four regular-season contests before finishing his rookie season on the practice squad.

There were built-in challenges beyond just his undrafted status. Heflin also aggravated a foot issue he's been dealing with since birth that required a minor corrective procedure in the offseason.

The good news was the one-month recovery didn't disrupt his preparation and allowed Heflin to report for camp feeling the strongest and most mobile of his football career.

Of course, his internal drive still burns fiercely, as well.

"It shows that I just want to be there where I can earn trust with the front office and the players here," Heflin said. "We obviously have a really high ceiling in our room and I'm just trying to bring up the floor and trying to close that gap."

Heflin is extremely self-aware. He knew where he still needed to improve after his rookie year. While run-stopping will forever be his bread and butter, Heflin wants to be more active and relentless when pushing the pocket against the pass in 2022.

When opportunity presents itself, Heflin has to capitalize. Because if he doesn't, someone else will. Of the nine defensive linemen currently on the Packers' roster, just Heflin and rookie Akial Byers are the only ones who weren't drafted into the NFL.

Heflin doesn't worry about the numbers or the odds. Based on experience, he believes all that does is cause distractions and take his focus away from where it should be.

Instead, Heflin's eyes and ears are tuned into his coaches and the veterans on the defensive line with the hope of penning the next chapter in his unlikely story.

"I got nothing to lose," Heflin said. "I just try to have faith in God and faith in my ability to prepare. Just listen to what the coach is telling you. They don't ever steer you wrong. They're going to give you a nugget. It's on you to take it and use it."