Like many adolescents, rookie defensive end Derrick Shelby had a favorite athlete. In his case it was defensive end Julius Peppers.

And, like many kids, Shelby realized as he grew up that he did not have the superhuman gifts of his favorite athlete.

But, unlike others, Shelby would not let that dose of reality stand in his way of fulfilling his dream to play in the NFL. Nor would he let the fact that he had never been a star at the high school or college level. Or that he had not been drafted.

Now this undrafted, undersized rookie from Utah is on the cusp of making the 53-man roster for the Miami Dolphins.

“I liked Julius Peppers, but as you grow up you see that you don’t have the same gifts as those guys,” Shelby said. “You’ve just got to find your own way, and that’s what I did.”

Shelby’s NFL plan was conventional enough: graduate, get drafted and make a team. Shelby completed the first step, he graduated from Utah last fall, but was derailed by the second one, as he failed to get drafted.

Unlike the second step, though, Shelby has more of an active role in ensuring that the third step goes according to his plan.

“I just figured I had that much more to prove,” Shelby said of the draft disappointment. “Going undrafted, you’re not really a guy that they look for to really step up and count on, but you come out here to work and be that guy.”

So far things have gone well for Shelby. He is listed as part of the second string on the latest depth chart and had two solo tackles, including one of the team’s five tackles for loss, during his preseason debut Friday against the Buccaneers.

Of the 16 undrafted college free agents the Dolphins signed in May, just two others are listed as high as the second team.

“I think he plays relatively quick,” Philbin said. “I think he’s coachable. … He’s obviously got a learning curve as a young player, [but] I think he gets it. He’s a quick study.”

Shelby’s agent, David Canter, said that what has him most convinced that Shelby is close to making the team is the large amount of attention the rookie has been getting recently.

“There’s been sort of a shift away from when he was first here and the coaches didn’t really talk to him much, didn’t really work with him much,” Canter said.

“Now, it seems like they’re on him. Any little mistake he makes, they’re yelling at him. Any tweak in his game, they’re fine-tuning. I think that reflects their belief that he may end up making this 53-man [roster] and be in the rotation,” he said.

For his part, Shelby said he is ignoring this good buzz and did not even admit to hearing it.

“I’m not here to get press and be mentioned by coaches: I’m here to play football,” Shelby said.

He said he likes being in the underdog role and having to prove himself. That is how he found his footing at Utah, where an injury to the starting defensive tackle meant that the then-250-pound freshman was the starter for the last 10 games of the season. That team went 13-0.

“I’m pretty sure I was a surprise [my freshman year],” Shelby said. “Nobody thought somebody 250 [pounds] could play defensive tackle. I think that helps me today, just being undersized and things like that. I’ve already experienced that, and I know what leverage to take in order to beat the blocks of the bigger guys.”

Utah is also where he learned to deal with the “grind,” as Shelby put it, something that he said has helped him at training camp.

“I’m sure that if you can succeed in that program you can succeed anywhere,” he said of his alma mater.

By his senior year, Shelby had put on 20 pounds and switched to defensive end, a position more suited for his build. He finished the season with 55 tackles and five sacks.

The numbers were good enough to make him first-team All-Pac-12 but not enough for him to be drafted, or, in his eyes to even be considered one of Utah’s stars.

“I’ve never been a star in my life,” Shelby said, chuckling at the possibility. “I’ve just been a guy who goes out and does his job, and that’s fine with me. … When you’re the underdog, it gives you that much more motivation. Sometimes you can come out here and it’s hot and it’s hard to work, but just think that nobody picked you to win, and you just come out here and win.”

Shelby still has a long road ahead before a spot on the roster is ensured, and he still describes himself on his Twitter profile as someone who is “chasing the dream.”

But if he does find his name on the Dolphins roster next month, Shelby said he is going to change the wording.

“If I end up making the team, it will be ‘dream fulfilled,’ and I’ve just got to stay in that dream as long as I can,” he said.