ENGLEWOOD, Colo. --The circumstances have changed and the stakes now ascend into the Colorado sky like a Rocky Mountain fourteener, but there's nothing new about taking on challenges for Steven Johnson.

When the Broncos' second-year linebacker steps onto the buzzing practice fields of training camp in several weeks, he will enter the mix in competing for playing time at the middle linebacker position.

It's a competition Johnson relishes because he believes it will help him grow significantly as a player – and, given Johnson's history as a former walk-on at the University of Kansas and an undrafted free agent in the NFL, he's no stranger to meeting challenges on the gridiron with unrelenting enthusiasm and desire.  

"Man, (the competition) has to make you better – it's either going to make you better or you won't be here," Johnson said during Broncos minicamp in June. "You just want to go out there every day and put your best foot forward and continue to get better each and every day."

"I'm just upping the ante for myself and it's just being able to make myself more accountable."

After contributing almost exclusively on special teams as a rookie in 2012, increased accountability is critical for Johnson in vying for a significantly increased workload on the Broncos defense this season.

Johnson led the team with 10 special teams tackles in 2012 and forced a fumble against Baltimore during a 34-17 Broncos victory in December.

Transitioning to the next level, however, demands a leap in responsibilities and expectations – something Johnson acknowledges.

"I feel as though, mentally, I'm trying to step into a new role," Johnson said. "So it's going to be a little bit more difficult, there's going to be more competition. Last year, I'm coming in trying to make the team, do the best I can on special teams. Now, I want to have a significant role on defense as well as on special teams."

Johnson noted that he's more comfortable with the playbook and the terminology in his second season, but he also credited the competitiveness of his fellow middle linebackers with helping his personal development and with strengthening the position collectively. 

"I do appreciate all the linebackers and being able to compete against them every day," Johnson said. "It's a privilege and an honor to be able to do that at this level."

The path for progressing from undrafted free agent to key defensive contributor is well-illuminated on the Broncos defense. 

Linebacker Wesley Woodyard, cornerback Chris Harris and cornerback Tony Carter all were undrafted – and all three set strong precedents as playmakers on defense. 

Harris – Johnson's former teammate at Kansas – has been particularly inspirational in setting an example for Johnson to take after.

"(Harris) just goes out there every day and works hard and competes. As a professional athlete, I look up to somebody like that so I follow his footsteps a little bit," Johnson said. "He paved the way. It's great to have somebody you know and who's been there and walked through that."

Johnson noted that he's latched onto Harris as a model for improving his coverage abilities.

"I just continue to train with him and work out with him because he sticks the best receivers in the league," Johnson said. "So if I can get footwork like him, then I can stick a receiver too."

Johnson is training with Harris during the time off, focusing heavily on footwork – which Johnson identified as the most important aspect of his game that he's worked towards improving.

"Right now, it's just efficient movement – being able to get out of my breaks and stuff like that," Johnson said. "(I'm) continuing to study my playbook and just becoming a smarter and more efficient player."

If history is any indicator, Johnson will continue working hard to contribute in any way possible for the Broncos.

In high school, Johnson didn't start until his senior season.

Once he did, he led all of Pennsylvania in tackles.

A severe left knee injury in prep school nearly ended Johnson's career and squelched almost all recruiting interest.

When Johnson finally unlocked the opportunity to play Division I college football, he had to earn it as a walk-on at Kansas.

Johnson finished his collegiate career by leading the Big 12 in tackles in his final season.

Now, he looks to turn the page to another chapter in his football career in transforming from undrafted free agent to contributor on the Broncos defense. 

"I'm just very blessed and fortunate to be able to get some reps out there," Johnson said. "I'm going to continue working hard and hopefully it will all work out for me and I'll be able to get some reps on Sundays when the season comes."