It's hard to move five feet in an NFL locker room without finding a player who believes he is underutilized.

D.J. Foster lives on the other end of the spectrum. As a former undrafted free agent, the Cardinals running back relishes any work he is afforded, keenly aware his NFL dream can disappear at any time.

That's why the 2018 preseason was so reassuring. Foster was routinely praised by coach Steve Wilks in training camp and seemed a shoo-in to make the active roster as a reserve ball-carrier and key special teams cog.

"I was really happy," Foster said. "I was playing good ball. I was excited."

And then – pop.

In the third exhibition game in Dallas, Foster suffered a season-ending torn ACL while covering a kickoff. As a former star at both Scottsdale Saguaro High School and Arizona State, Foster received countless condolences, but after a while, he inevitably faded into the background as the season moved on without him.

"You take the first couple weeks feeling sorry for yourself," Foster said. "Everyone needs that. You need that feeling of sadness. That's OK because it is a big deal. But you have to switch that mindset quick, to go from that to, 'OK, I need to get back. This is my future. This is my career. If I want to play again, I have to take this seriously.'"

Foster has been rehabilitating the knee for the past several months, putting in daily sessions with the Cardinals' training staff. While his teammates are scattered around the country enjoying time off, Foster continues to grind this offseason, intent on getting back to full speed for 2019.

"I feel good," Foster said. "I'm moving very well. The trainers have done a great job of keeping me on schedule and I'm on track to get back whenever time that is. I'm ahead of schedule. I'm just trying to come every day and work hard. It's hard to transition from being a football player to this is my job. My job is to get healthy. That's it. It's been nice being home and being around family. That's helped me a lot."

Foster grew up in Scottsdale and has pulled off the rare feat of playing high school, college and professional football in Arizona. He is a restricted free agent, but hopes to remain with the Cardinals.

While a coaching change eliminated the goodwill Foster built up with Wilks, the general manager that plucked him off the Patriots practice squad in 2017 – Steve Keim – is still in charge of the roster construction.

"I felt like I was playing good ball before this happened, so hopefully they still have good memories and thoughts on their mind," Foster said. "I'd love to be back here, but whatever happens, happens."

Foster seems like a good fit for new coach Kliff Kingsbury's pass-friendly style, as versatility is one of his trademarks. Foster played wide receiver in his final season at Arizona State and has elite hands for a running back.

"I saw a lot of what he did in college, and the league's starting to switch to that anyway, when it comes to spreading backs out and using them in more ways than just running back," Foster said. "I feel like, working on myself and my game over the years, I can try to adapt to any system and scheme. Special teams is big for me, and think I can run between the tackles, pass protect, do the scat-back, third-down stuff as well. Just whatever system, whatever type of offense he brings, I'll just try to work hard, adapt to that and find a role in it."